Composite film

Abstract

A composite membrane comprising: a) a first layer comprising a first porous support and a first ionic polymer present in the pores of the first porous support; b) a second layer comprising a second porous support and a second ionic polymer present in the pores of the second porous support; c) a third layer comprising a third porous support, a third ionic polymer, and a fourth ionic polymer, wherein the third ionic polymer is present in the pores of the third porous support; wherein: (i) one of the first ionic polymer and the second ionic polymer is a cationic polymer and the other is an anionic polymer; (ii) the third layer c) is interposed between the first layer a) and the second layer b); (iii) the third ionic polymer comprises a network of pores, and the fourth ionic polymer is present within the pores of the third ionic polymer; and (iv) one of the third ionic polymer and the fourth ionic polymer is a cationic polymer and the other is an anionic polymer.

Description

[0001] This invention relates to composite membranes and methods for their preparation and use. Ion exchange membranes are used in electrodialysis, reverse electrodialysis, electrolysis, diffusion dialysis, and many other processes. Typically, ion transport across the membrane occurs under the influence of a driving force, such as an ion concentration gradient or a potential gradient.

[0002] Ion exchange membranes are typically classified into cation exchange membranes and anion exchange membranes based on their primary charge. Cation exchange membranes contain negatively charged groups that allow cations to pass through but repel anions, while anion exchange membranes contain positively charged groups that allow anions to pass through but repel cations. Bipolar ion exchange membranes possess both cation and anion layers.

[0003] Some ion exchange membranes contain porous supports that provide mechanical strength. Because of the presence of ionicly charged polymers that differentiate ions with opposite charges and porous supports that provide mechanical strength, these membranes are often referred to as "composite membranes."

[0004] For example, composite membranes are known from US 4,253,900, which describes a bipolar membrane comprising a single bead layer of ion exchange resin. WO2017 / 205458 and McClure’s article in ECS Transactions, 2015, 69(18), 35-44, describe a bipolar membrane comprising a connecting layer of interpenetrating polymer nanofibers or microfibers of anion exchange polymers and cation exchange polymers. Other examples of composite membranes are described, for example, in EP3604404, in which one layer comprises ion exchange resin powder; and US4673454, which discloses the use of ion exchange resins in an interfacial layer. It is desirable to provide composite membranes with improved properties, such as high permeation selectivity, low resistivity, good mechanical strength, low swelling under aqueous conditions, and stability at extreme pH levels. Ideally, such membranes should be produced quickly, efficiently, and inexpensively.

[0005] According to a first aspect of the present invention, a composite membrane is provided, comprising:

[0006] a) A first layer comprising a first porous support and a first ionic polymer present in the pores of the first porous support;

[0007] b) A second layer comprising a second porous support and a second ionic polymer present in the pores of the second porous support;

[0008] c) A third layer comprising a third porous support, a third ionic polymer, and a fourth ionic polymer, wherein the third ionic polymer is present in the pores of the third porous support;

[0009] in:

[0010] (i) One of the first ionic polymer and the second ionic polymer is a cationic polymer, and the other is an anionic polymer;

[0011] (ii) The third layer c) is located between the first layer a) and the second layer b);

[0012] (iii) The third ionic polymer comprises a porous network, and the fourth ionic polymer is present within the pores of the third ionic polymer; and

[0013] (iv) One of the third ionic polymer and the fourth ionic polymer is a cationic polymer, and the other is an anionic polymer.

[0014] In this specification (including its claims), the verb "comprising" and its variations are used in a non-limiting sense to mean including items following the word, but not excluding items not specifically mentioned. Furthermore, the indefinite article "a" or "an" refers to an element that does not exclude the possibility of more than one element, unless the context explicitly requires that there be only one element. Therefore, the indefinite article "a" or "an" generally means "at least one". Additionally, in this specification, a third ionic polymer comprising a porous network is generally abbreviated as "third ionic polymer".

[0015] Preferably, the porous support is non-ionic.

[0016] In a preferred embodiment, the third ionic polymer can be obtained by phase separation of the third ionic polymer from the composition used to prepare the third ionic polymer. In this way, a third ionic polymer comprising a porous network can be obtained, and the pores can be used to receive a fourth ionic polymer (or a curable composition used to prepare the fourth ionic polymer) to create a third layer c). In one embodiment, the curable composition used to prepare the fourth ionic polymer is the same as the curable composition used to prepare the first ionic polymer. In this way, a composite film in which the first ionic polymer and the fourth ionic polymer are the same can be obtained.

[0017] Preferably, the third ionic polymer comprises a porous first polymeric domain, which includes ionic groups and a pore network. Preferably, the fourth ionic polymer comprises a second polymeric domain, which includes ionic groups with opposite charges to the ionic groups of the first polymeric domain. In this embodiment, the second polymeric domain is located within the pores of the first polymeric domain (i.e., within the pores of the third ionic polymer).

[0018] In a particularly preferred embodiment, in the third layer c), the third and fourth ionic polymers exist as a co-continuous network comprising the third and fourth ionic polymers. The third and fourth ionic polymers preferably provide two separate, continuous, mixed, unmixed, unencapsulated, and non-fibrillar polymer domains, one with an anionic charge and the other with a cationic charge. Optionally, the third layer c) comprises one or more additional polymer domains, each with an anionic or cationic charge.

[0019] In a preferred embodiment, the fourth ionic polymer is chemically identical to the first ionic polymer in the first layer a). In another preferred embodiment, the third ionic polymer has the same charge and / or is chemically identical to the second ionic polymer in the second layer b).

[0020] In another preferred embodiment, the fourth ionic polymer is chemically identical to the first ionic polymer in the first layer a), and the third ionic polymer is chemically identical to the second ionic polymer in the second layer b).

[0021] The third layer (c) preferably comprises at least two continuously mixed polymer domains (one domain derived from a third ionic polymer and the other from a fourth ionic polymer) having a large contact area with each other. This can be achieved by the third and fourth ionic polymers comprising a porous network, wherein the fourth ionic polymer is different from the third ionic polymer (e.g., one is cationic and the other is anionic) and exists within the pores of the third ionic polymer. Due to this large contact area between the two (or more) ionic polymers present in the third layer, when the composite membrane is used as a bipolar membrane, it dissociates into H2 per unit time. + and OH - The increased amount of water molecules leads to an increase in the productivity of the composite bipolar membrane.

[0022] The large contact area between the third and fourth ionic polymers present in the third layer is preferably provided by a co-continuous network, wherein two (or more) polymer domains originating from the third and fourth ionic polymers carry opposite charges (i.e., one domain has an anionic charge, while the others have a cationic charge). The advantage of the co-continuous network is that newly generated anions (e.g., OH-) at the interface between the third and fourth ionic polymers (i.e., the interface between the two polymer domains) are readily available. - ) and cations (e.g., H+) +Immediately after its formation, the ions are separated into individual polymer domains, preventing ion recombination. Furthermore, the adhesion between the third and fourth ionic polymers in the third layer (i.e., the adhesion between the first and second polymer domains) is very strong due to entanglement and the large contact area between the third and fourth ionic polymers in the third layer. This strong adhesion between the third and fourth ionic polymers prevents / reduces the so-called ballooning effect, in which large water-filled bubbles form at the interface between the positively charged and negatively charged polymers of the bipolar film, where OH... - and H + They may recombine to form water.

[0023] The composite membrane of the present invention preferably includes an interface (first interface) between the first layer a) and the third layer c) and an interface (second interface) between the third layer c) and the second layer b). Preferably, the first interface and the second interface are uninterrupted, with no gaps and / or spaces between the first layer a) and the third layer c), and with no gaps and / or spaces between the third layer c) and the second layer b).

[0024] In one embodiment, the third layer c) comprises a blend of two consecutive polymer domains derived from the third and fourth ionic polymers, respectively, wherein one domain (derived from the fourth ionic polymer) is located within the other domain (derived from the third ionic polymer), forming a co-continuous network (the fourth ionic polymer within the third ionic polymer).

[0025] Preferably, each of the first and second polymer domains is continuous and substantially comprises a single covalently linked carbon backbone, such that it is interconnected with itself.

[0026] Preferably, the polymer domains are not encapsulated, not separated, not interrupted, and are non-fibrous (e.g., not made by electrospinning).

[0027] The co-continuous network preferably comprises two (or more) continuous polymer domains within the same volume. In other words, the two (or more) continuous polymer domains coexist closely in the same volume and are non-uniformly mixed, such that each phase can be independently distinguished. Therefore, the third and fourth ionic polymers are discrete and non-uniformly mixed with each other, and can be independently distinguished from the other, for example, by cutting the third layer c) and examining its cross-section using a scanning electron microscope. Thus, the third layer c) is very different from a layer formed simply by mixing two polymers with opposite charges or by mixing two different curable compositions and then curing the mixture.

[0028] In this invention, the third layer c) comprises a porous support, and within the porous structure of this support, a third ionic polymer comprising a pore network and a fourth ionic polymer present within these pores preferably provide two polymer domains (a co-continuous network), one carrying an anionic charge and the other carrying a cationic charge. Two (or more) polymer domains (one from the third ionic polymer and the other from the fourth ionic polymer present within the pore network of the third ionic polymer) occupy the pores of the porous support, and preferably include a seamless (third) interface (the first and second interfaces are located between the third layer c) and the first layer a) and the second layer b), respectively). Therefore, the composite membrane preferably includes an interface between the third layer c) and the first layer a), an interface between the third layer c) and the second layer b), and a third interface between the third ionic polymer and the fourth ionic polymer within the third layer c). Preferably, this third interface is uninterrupted, with no gaps and / or spaces between the third and fourth ionic polymers. Preferably, this third interface is not an interface between the ionic polymer and molten / compressed fibers, beads, or particles.

[0029] Preferably, the volume ratio of the third ionic polymer to the fourth ionic polymer in the third layer c) is such that the volume ratio of the anionic polymer to the cationic polymer in the third layer c) is 0.1 to 0.9, more preferably 0.2 to 0.8, particularly 0.3 to 0.7, for example about 0.4, about 0.5 or about 0.6.

[0030] In one embodiment, the third ionic polymer is obtained by a method comprising, for example, polymerization-induced phase separation of the third ionic polymer with the composition used to prepare the polymer, more preferably photopolymerization-induced phase separation. This preference arises because this method is particularly adept at providing a third ionic polymer capable of receiving a fourth (oppositely charged) ionic polymer. In this method, the third ionic polymer is preferably formed via photopolymerization.

[0031] Preferably, the third ionic polymer comprises a pore network with an average pore size of less than 5 μm, more preferably less than 2 μm, and particularly less than 1.2 μm. The pores between the third ionic polymers can then be filled with a curable composition, which can then be cured to provide a fourth ionic polymer within the pore network of the third ionic polymer. In a preferred embodiment, the pore network of the third ionic polymer is substantially or completely filled with the fourth ionic polymer. As a result, the third layer results in a third porous support filled with the third ionic polymer, and the pore network of the third ionic polymer filled with the fourth ionic polymer (with opposite charges). Thus, the third and fourth ionic polymers can provide a continuous network comprising two polymer domains: one from the third ionic polymer and the other from the fourth ionic polymer. In a preferred embodiment, this continuous network contains no other polymers (except for any polymers present in the porous support). In one embodiment, covalent bonds are present that link the third and fourth ionic polymers together. In fact, the pore network in the porous third ionomer can include more than one ionomer. For example, the pore network in the third ionomer can include a first ionomer (derived from a first curable composition) and an optional second ionomer (derived from a second curable composition), such that the first polymer acts as a fourth ionomer to partially fill the pores of the third ionomer, and the second ionomer fills the remaining pores. Additionally, if necessary, the pore network in the porous third ionomer can include one or more other polymers.

[0032] According to a second aspect of the present invention, a method for preparing the composite membrane of the first aspect of the present invention is provided, comprising the following steps:

[0033] I. Provide a first porous support, a second porous support, and a third porous support;

[0034] II. Provides a first curable composition comprising a curable ionic compound, a second curable composition comprising a curable ionic compound having an opposite charge to the curable compound present in the first curable composition, a third curable composition comprising a curable ionic compound, and a fourth curable composition comprising a curable ionic compound having an opposite charge to the curable compound present in the third curable composition;

[0035] III. Impregnate the third porous carrier with the third curable composition;

[0036] IV. Curing the third curable composition present in the third porous support to form a layer comprising the third porous support and a third ionic polymer comprising a pore network (hereinafter referred to as the “base layer” for the sake of brevity);

[0037] V. Impregnate the porous network of the third ionomer with the fourth curable composition;

[0038] VI. Bring the first curable composition into contact with a first side of the substrate;

[0039] VII. Bring the second curable composition into contact with the second side of the substrate; and

[0040] VIII. The first curable composition, the second curable composition, and the fourth curable composition are cured in any order or simultaneously to form the first ionic polymer, the second ionic polymer, and the fourth ionic polymer, respectively;

[0041] in:

[0042] (a) When the first curable composition is cured, the first curable composition includes the first porous carrier; and

[0043] (b) When the second curable composition is cured, the second curable composition includes the second porous carrier.

[0044] The method of the second aspect of the invention can be carried out in a variety of different ways, but is not limited to those described in more detail below.

[0045] In one embodiment of the method, when the first curable composition is applied to a first side of the substrate, the first curable composition includes a first porous carrier. For example, the first porous carrier can be impregnated with the first curable composition, and the impregnated carrier thus prepared can then contact the substrate. In one embodiment, at least some of the first curable composition in excess of the composition present in the first porous carrier enters the pore network in the substrate. Then, when the first composition cures to form a first ionic polymer, the first porous carrier adheres firmly to the substrate by means of the first ionic polymer. Furthermore, the curing of the first curable composition within the pore network in the substrate also forms a fourth polymer, thereby partially or completely forming a third layer c). In this embodiment, the first polymer present in the pores of the substrate and the first polymer forming the first layer a) are covalently bonded, thereby forming a very strong bond between the first layer a) and the third layer c).

[0046] In an alternative embodiment, after the first curable composition has been applied to a first side of the substrate, a first porous carrier is applied to the first curable composition. For example, the substrate is coated with the first curable composition (whereby the pores of the substrate are at least partially impregnated by the first curable composition), and then the first porous carrier is brought into contact with the first curable composition present on the substrate.

[0047] As in the preceding embodiments, when the first composition is cured to form a first ionic polymer, the first porous carrier adheres firmly to the substrate by means of a large number of covalent bonds within the first ionic polymer.

[0048] Similarly, in one embodiment, when the second curable composition is applied to a second side of the substrate, the second curable composition includes a second porous carrier. For example, the second porous carrier can be impregnated with the second curable composition, and the impregnated carrier thus prepared can then contact the substrate. In one embodiment, at least some of the excess composition present in the second porous carrier enters the remaining pores in the substrate. Preferably, after the second curable composition contacts the substrate, no air residue remains at the interface between the substrate and the second curable composition. Then, when the second composition cures to form a second ionomer, the second porous carrier adheres firmly to the substrate by means of the second ionomer.

[0049] In an alternative embodiment, after the second curable composition has been applied to a second side of the substrate, a second porous carrier is applied to the second curable composition. For example, the substrate is coated with the second curable composition, and then the second porous carrier is brought into contact with the second curable composition present on the substrate. As in the preceding embodiments, when the second composition cures to form a second ionomer, the second porous carrier adheres firmly to the substrate by means of the second ionomer.

[0050] In one embodiment, the first curable composition comprising a first porous carrier is cured before the second composition comprising a second porous carrier is cured. Alternatively, the first curable composition comprising the first porous carrier and the second composition comprising the second porous carrier may be cured simultaneously.

[0051] In one embodiment, a first curable composition comprising a first porous carrier and a second curable composition comprising a second porous carrier are applied simultaneously or in any order to a first side and a second side of a substrate, respectively. Preferably, the first curable composition comprising the first porous carrier is applied to the first side of the substrate, and then the second curable composition comprising the second porous carrier is applied to the second side of the substrate, or the first curable composition comprising the first porous carrier and the second curable composition comprising the second porous carrier are applied simultaneously to the first side and the second side of the substrate, respectively.

[0052] In another embodiment, a first side of the substrate is coated with a first curable composition, a second side of the substrate is coated with a second curable composition, and a first porous carrier and a second porous carrier are applied simultaneously or in any order to the first side of the substrate coated with the first curable composition and the second side of the substrate coated with the second curable composition, respectively.

[0053] In yet another embodiment, the fourth curable composition is different from the first curable composition and is applied to and cured on a first side of the substrate, and then the first curable composition (which may or may not contain the first porous carrier) is applied to the first side of the substrate.

[0054] As a result, a composite membrane is formed, which includes a third ionic polymer and a fourth ionic polymer in the third layer, a first ionic polymer in the first layer, and a second ionic polymer in the second layer.

[0055] In this invention, in addition to the porous carrier, the third ionic polymer preferably does not contain linear structures (e.g., fibers). Furthermore, preferably, the third ionic polymer does not contain (molten) beads or encapsulated structures.

[0056] As described above, the third layer c) can be obtained by a method comprising forming a third ionic polymer containing a porous network from a third curable composition by polymerization-induced phase separation, impregnating the porous network with a fourth curable composition suitable for forming a fourth polymer, and curing the fourth curable composition within the porous network of the third ionic polymer and optionally on the surface of the third ionic polymer, so as to simultaneously produce one of the other layers (i.e., layer a) while producing the third layer c). Attached Figure Description

[0057] Figure 1A A cross-section of a typical composite membrane described in the prior art is shown.

[0058] Figure 1B A cross-section of the composite membrane of the present invention is shown.

[0059] Figure 2 An embodiment of the method for preparing the composite membrane of the present invention is shown.

[0060] exist Figure 1A In the middle, layer 1 is a polymer layer, layer 3 is a central layer including fibrous elements, and layer 2 is another polymer layer.

[0061] exist Figure 1B In this structure, layer 1 is a first layer (a) containing a first ionomer and a porous support (not shown). Layer 3 is a third layer (c) containing a third and a fourth ionomer, which are respectively black and white. The third ionomer (black) is located within the pores of the third porous support (not shown), and the fourth ionomer (white) is located within the pores of the third ionomer (black). Layer 2 is a second layer (b) containing a second porous support (not shown).

[0062] exist Figure 2The manufacturing unit includes an unwinding station (1), a curable composition application station (2), a metering station (3), a curing station (4), a drying station (5), a curable composition application station (6), an unwinding station (7), a laminating station (8), a curing station (9), and a membrane collection station (10).

[0063] In one embodiment, the porous carriers present in the first layer a), the second layer b), and the third layer c) are chemically and physically identical.

[0064] In another embodiment, the porous carriers present in two of layers a), b), and c) are chemically and physically identical to each other, and the porous carriers present in the remaining layers of layers a), b), and c) are chemically and / or physically different from the porous carriers present in the other two layers.

[0065] In yet another embodiment, the porous support present in each of layers a), b), and c) is chemically and / or physically different from the porous support present in the other two of layers a), b), and c). This preference depends on the intended use of the composite membrane.

[0066] Examples of porous supports that can be contained in layers a), b), and / or c) include woven and nonwoven synthetic fabrics and extruded membranes. Examples include wet and dry nonwoven materials, spunbond and meltblown fabrics, and nanofiber webs made of, for example, polyethylene, polypropylene, polyacrylonitrile, polyvinyl chloride, polyphenylene sulfide, polyester, polyamide, polyaryletherketone (e.g., polyetheretherketone) and copolymers thereof. Porous supports can also be porous membranes, such as polysulfone, polyethersulfone, polyphenylene sulfone, polyphenylene sulfide, polyimide, polyetherimide, polyamide, polyamide-imide, polyacrylonitrile, polycarbonate, polyacrylate, cellulose acetate, polypropylene, poly(4-methyl-1-pentene), polyvinylidene fluoride, polytetrafluoroethylene, polyhexafluoropropylene, and polychlorotrifluoroethylene membranes and their derivatives.

[0067] Preferably, the porous carriers present in the first layer a), the second layer b), and the third layer c) each independently have an average thickness of 10 to 200 μm, more preferably 20 to 150 μm, and particularly 50 to 100 μm.

[0068] Preferably, the porosity of the porous carrier is 30% to 95%. The porosity of the carrier can be measured using a porosimeter such as Porolux from IB-FT GmbH, Germany. TM 1000 was measured.

[0069] One or more porous supports can be treated to alter their surface energy, for example, to a value higher than 45 mN / m, preferably higher than 55 mN / m. Suitable treatments include corona discharge treatment, plasma glow discharge treatment, flame treatment, ultraviolet irradiation treatment, or chemical treatment, for example, to improve the wettability and adhesion of the porous support.

[0070] Commercially available porous carriers are available from many sources, such as Freudenberg Filtration Technologies (Novatexx materials), Lydall Performance Materials, Celgard LLC, APorous Inc., SWM (Conwed Plastics, DelStar Technologies), Teijin, Hirose, Mitsubishi Paper Mills Ltd and Sefar AG.

[0071] Preferably, each carrier is an independent polymeric carrier. Preferred carriers include woven and nonwoven synthetic fabrics or extruded films that do not contain covalently bound ionic groups.

[0072] Preferably, the first layer a), the second layer b), and the third layer c) of the composite film each independently have an average thickness of 10 μm to 200 μm, more preferably 20 μm to 150 μm, and particularly 50 μm to 100 μm.

[0073] Preferably, the average thickness of the composite film is 30 μm to 600 μm, more preferably 60 μm to 450 μm, and particularly 150 μm to 300 μm.

[0074] Preferably, the composite membrane of the present invention is a composite bipolar membrane.

[0075] Preferably, the first ionomer can be obtained by a method comprising curing a first curable composition, the first curable composition comprising:

[0076] (a1) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group;

[0077] (b1) 1 to 88% by weight of a curable compound comprising at least two olefinic unsaturated groups and optional ionic groups;

[0078] (c1) 0 to 10% by weight of a free radical initiator; and

[0079] (d1) 0 to 55% by weight of solvent.

[0080] Preferably, the second ionomer can be obtained by a method comprising curing a second curable composition, the second curable composition comprising:

[0081] (a2) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group having an opposite charge to the curable compound present in the first curable composition;

[0082] (b2) 1 to 88% by weight of a curable compound comprising at least two olefinic unsaturated groups and optional ionic groups (which carries an opposite charge to the curable compound present in the first curable composition);

[0083] (c2) 0 to 10% by weight of a free radical initiator; and

[0084] (d2) 0 to 55% by weight of solvent.

[0085] As described above, the third ionic polymer is preferably obtained by a method comprising polymerization-induced phase separation of the third ionic polymer with a third curable composition used to prepare the third ionic polymer. This method is particularly suitable for providing the third ionic polymer in the form of a porous network capable of receiving a fourth curable composition (which may be the same as or different from the first curable composition) to prepare the fourth ionic polymer within the porous network (optionally, on the surface of the third ionic polymer, to provide the first layer a in a very efficient manner).

[0086] In this way, a porous network present in the third ionomer can be prepared, then impregnated with a fourth curable composition suitable for forming the fourth polymer, and the fourth curable composition is cured within the pores of the third ionomer and optionally on the surface of the third ionomer, so as to simultaneously produce layer a) while producing the third layer c).

[0087] Preferably, the third ionic polymer comprising a porous network can be obtained by a method including curing a third curable composition comprising:

[0088] (a3) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group;

[0089] (b3) 1 to 70% by weight of a curable compound comprising at least two olefinic unsaturated groups and optional ionic groups;

[0090] (c3) 0 to 10% by weight of free radical initiator; and

[0091] (d3) 20 to 98% by weight of solvent.

[0092] Preferably, component (a3) ​​in the third curable composition has ionic groups with opposite charges to the curable compounds present in the first curable composition.

[0093] Preferably, the fourth ionic polymer can be obtained by a method comprising curing a fourth curable composition, which falls within the definition provided above for the first curable composition. The fourth curable composition may be the same as or different from the first curable composition. Preferably, the fourth curable composition comprises a curable composition having an olefinically unsaturated group and ionic groups having an opposite charge to the curable compounds present in the third curable composition. Therefore, the fourth ionic polymer can be obtained by a method comprising curing a fourth curable composition, which includes:

[0094] (a4) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group having an opposite charge to the curable compound present in the third curable composition;

[0095] (b4) 1 to 88% by weight of a curable compound comprising at least two olefinic unsaturated groups and optional ionic groups (which carries the opposite charge to the curable compound present in the third curable composition);

[0096] (c4) 0 to 10% by weight of free radical initiator; and

[0097] (d4) 0 to 55% by weight of solvent.

[0098] The components present in the curable composition may be mixtures of several compounds belonging to each of the respective categories. The amounts of each of components (a1), (a2), and (a4) are preferably 0 to 40% by weight.

[0099] The amount of component (a3) ​​is preferably 0 to 30% by weight, particularly 0 to 20% by weight.

[0100] The amounts of each of components (b1), (b2) and (b4) are preferably 5 to 80% by weight, particularly 10 to 70% by weight.

[0101] The amount of component (b3) is preferably 9 to 65% by weight, particularly 14 to 59% by weight, and even more particularly 19 to 49% by weight.

[0102] When the composition is intended to be cured by UV, visible light, or thermosetting, the curable composition preferably contains free radical initiators (components (c1), (c2), (c3)) and (c4). Alternative methods of curing include electron beam and gamma irradiation. These methods do not require free radical initiators. Therefore, the amounts of components (c1), (c2), (c3), and (c4) present in the relevant composition are preferably 0 to 2% by weight, more preferably 0.001 to 2% by weight (for UV, visible light, or thermosetting), and particularly 0.005 to 0.9% by weight.

[0103] The amounts of components (d1), (d2), and (d4) present in the relevant composition are preferably 20 to 45% by weight.

[0104] Preferably, the solvents used as components (d1), (d2), and (d3) are inert, i.e., they do not react with any other component of the curable composition. The amount of component (d3) is preferably 30 to 90% by weight, particularly 40 to 85% by weight, and more particularly 49 to 78% by weight.

[0105] Component (d3) is preferably a single solvent.

[0106] Component (d3) may optionally contain two or more inert solvents, at least one of which is a solvent for other components of the curable composition, and at least one of which is a non-solvent for a third ionic polymer formed, for example, by curing the composition through phase separation, thereby forming a third ionic polymer comprising a pore network capable of receiving a fourth curable composition.

[0107] Examples of inert solvents include water, alcohols, ethers, amides, ketones, sulfoxides, sulfones, nitriles, and organophosphorus solvents. Examples of alcohols that can be used as or for component (d3) (especially in combination with water) include methanol, ethanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and mixtures containing two or more of these. Water is particularly preferred.

[0108] Additionally, preferred inert organic solvents that can be used for component (d3) include dimethyl sulfoxide, dimethylimidazolinone, sulfolane, N-methylpyrrolidone, dimethylformamide, acetonitrile, acetone, 1,4-dioxane, 1,3-dioxolane, tetramethylurea, hexamethylphosphoramide, hexamethylphosphoric triamine, pyridine, propionitrile, butanone, cyclohexanone, tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, ethylene glycol diacetate, cyclopentylmethyl ether, methyl ethyl ketone, ethyl acetate, γ-butyrolactone, and mixtures containing two or more of these. Preferred solvents include dimethyl sulfoxide, N-methylpyrrolidone, dimethylformamide, dimethylimidazolinone, sulfolane, acetone, cyclopentylmethyl ether, methyl ethyl ketone, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, and mixtures containing two or more of these.

[0109] In one embodiment, component (d3) comprises at least one solvent from list (i) below and at least one solvent from list (ii) below:

[0110] List (i): isopropanol, methanol, ethanol, acetone, tetramethylurea, hexamethylphosphoramide, hexamethylphosphoric triamine, butanone, cyclohexanone, methyl ethyl ketone, tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, cyclopentylmethyl ether, propionitrile, acetonitrile, 1,4-dioxane, 1,3-dioxolane, ethyl acetate, γ-butyrolactone; and

[0111] List (ii): Water, Glycerin, Ethylene Glycol, Dimethyl Sulfoxide, Sulfonane, Dimethylimidazolinone, Sulfolane, N-Methylpyrrolidone, N,N-Dimethylformamide, N-Methylmorpholine, Acetonitrile, Acetone, 1,4-Dioxane, 1,3-Dioxolane, Tetramethylurea, Hexamethylphosphoramide, Hexamethylphosphoric acid triamine, Pyridine, Propanolon, Butanone, Cyclohexanone, Tetrahydrofuran, Tetrahydropyran, 2-Methyltetrahydrofuran, Ethylene glycol diacetate, Cyclopentylmethyl ether, Methyl ethyl ketone, Ethyl acetate, and γ-Butyrolactone.

[0112] In one embodiment, component (d3) comprises water and one or more solvents listed in (i).

[0113] Preferably, one of the first and second curable compositions comprises a curable compound having an olefinic unsaturated group and an anionic group, while the other comprises a curable compound having an olefinic unsaturated group and a cationic group. Furthermore, preferably, one of the third and fourth curable compositions comprises a curable compound having an olefinic unsaturated group and an anionic group, while the other comprises a curable compound having an olefinic unsaturated group and a cationic group.

[0114] Examples of curable compounds having olefinic unsaturated groups and anionic or cationic groups include compounds of the following formulas (A), (B), (CL), (SM), (MA), (MB-α), (C), (ACL-A), (ACL-B), (ACL-C), and / or (AM-B):

[0115]

[0116] In equations (A) and (B):

[0117] R A1 To R A3 Each can independently represent a hydrogen atom or an alkyl group;

[0118] R B1 To RB7 Each can independently represent an alkyl or aryl group;

[0119] Z A1 To Z A3 Each can be represented independently as -O- or -NRa-, where Ra represents a hydrogen atom or an alkyl group;

[0120] L A1 To L A3 Each independently represents a divalent linking group of alkylene, arylene, or a combination thereof;

[0121] R X This indicates a divalent linking group representing an alkylene group, an alkenylene group, an ynylene group, an arylene group, or a combination thereof; and

[0122] X A1 To X A3 Each can be independently represented as an organic or inorganic anion, preferably a halide ion or an aliphatic or aromatic carboxylic acid ion.

[0123] Examples of compounds of formula (A) or (B) include:

[0124]

[0125]

[0126] Synthetic methods can be found in, for example, US2015 / 0353721, US2016 / 0367980 and US2014 / 0378561.

[0127]

[0128] In equations (CL) and (SM):

[0129] L 1 Indicates alkylene or alkenylene;

[0130] R a R b R c and R d Each can independently represent a straight-chain or branched alkyl or aryl group.

[0131] R a and R b , and / or R c and R d They can form rings by combining with each other;

[0132] R 1 R 2 and R 3 Each independently represents a straight-chain or branched alkyl or aryl group, R 1 and R 2, or R 1 R 2 and R 3 They can combine with each other to form aliphatic heterocycles;

[0133] n1, n2, and n3 each independently represent integers from 1 to 10; and

[0134] X1 - X2 - and X3 - Each can be used independently to represent an organic or inorganic anion.

[0135] Examples of formulas (CL) and (SM) include:

[0136]

[0137] The synthesis method can be found in EP3184558 and US2016 / 0001238.

[0138]

[0139] In equations (MA) and (MB-α),

[0140] R A1 Indicates a hydrogen atom or an alkyl group;

[0141] Z 1 It represents -O- or -NRa-, where Ra represents a hydrogen atom or an alkyl group;

[0142] M + It can represent organic or inorganic cations, preferably hydrogen ions or alkali metal ions;

[0143] R A2 Indicates hydrogen atom or alkyl group,

[0144] R A4 This refers to an organic group that contains a sulfonic acid group and does not have an olefinic unsaturated group; and

[0145] Z 2 The designation is -NRa-, where Ra represents a hydrogen atom or an alkyl group, preferably a hydrogen atom.

[0146] Examples of formulas (MA) and (MB-α) include:

[0147]

[0148] Synthetic methods can be found, for example, in US2015 / 0353696.

[0149]

[0150] Synthetic methods can be found, for example, in US2016 / 0369017.

[0151]

[0152] In equation (C),

[0153] L 1 Indicates alkylene;

[0154] n represents an integer from 1 to 3, preferably 1 or 2;

[0155] m represents an integer of 1 or 2;

[0156] L 2 Indicates an n-valent linker group;

[0157] R 1 Indicates a hydrogen atom or an alkyl group;

[0158] R 2 Indicates -SO3 - M + or -SO3R 3- In multiple R 2 In the case of each R 2 Independently represented -SO3M + or -SO3R 3- ;

[0159] M + Indicates hydrogen ions, inorganic ions, or organic ions; and

[0160] R 3 Indicates alkyl or aryl.

[0161] Examples of formula (C) include:

[0162]

[0163] The synthesis method can be found in EP3187516.

[0164]

[0165] In equations (ACL-A), (ACL-B), (ACL-C), and (AM-B),

[0166] R and R' each independently represent a hydrogen atom or an alkyl group;

[0167] LL represents a single bond or a divalent linker;

[0168] LL 1 LL 1 '、LL 2 and LL 2Each of these groups independently represents a single bond or a divalent linking group; and A and A' each independently represent a sulfonyl group in the form of a free acid or salt; and

[0169] m represents 1 or 2.

[0170] Examples of formulas (ACL-A), (ACL-B), (ACL-C), and (AM-B) include:

[0171]

[0172] The synthesis method can be found in US2016 / 0362526.

[0173] Other suitable monomers include:

[0174]

[0175] Curable compositions can be cured by any suitable method, including thermosetting, photocuring, electron beam (EB) irradiation, gamma irradiation, and combinations thereof. However, curable compositions are preferably cured by photocuring, for example by irradiating the curable composition with ultraviolet light, thereby polymerizing the curable components present in the composition.

[0176] Examples of suitable thermal initiators that can be included in curable compositions include: 2,2'-azobis(2-methylpropionitrile) (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 2,2'-azobis(2,4-dimethylpentanonitrile), 2,2'-azobis(2-methylbutanonitrile), 1,1'-azobis(cyclohexane-1-carboxylonitrile), 2,2'-azobis(4-methoxy-2,4-dimethylpentanonitrile), dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide, 1-[(1-cyano-1-methylethyl)azo]formamide, 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis(2-propionamide) 2,2'-Azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-Azobis[2-(2-imidazolin-2-yl)propane] disulfate dihydrate, 2,2'-Azobis[N-(2-carboxyethyl)-2-methylpropane] hydrate, 2,2'-Azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl] Propane dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(1-imino-1-pyrrolidin-2-ethylpropane) dihydrochloride, 2,2'-azobis{2-methyl-N-[1,1-di(hydroxymethyl)-2-hydroxyethyl]propionamide} and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].

[0177] Examples of suitable photoinitiators that can be included in curable compositions include aromatic ketones, acylphosphine compounds, aromatic onium salts, organic peroxides, thiocyanates, hexaaryl biimidazole compounds, ketoxime esters, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having carbon-halogen bonds, and alkylamine compounds. Preferred examples of aromatic ketones, acylphosphine oxide compounds, and thiocyanates include compounds having a benzophenone backbone or a thioxanone backbone, described in “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY”, pp. 77-117 (1993). More preferred examples include α-thiobenzophenone compounds described in JP1972-6416B (JP-S47-6416B), JP1972-3981B (JP-S47-3981). Benzoin ether compounds described in B), α-substituted benzoin compounds described in JP1972-22326B (JP-S47-22326B), benzoin derivatives described in JP1972-23664B (JP-S47-23664B), aromatic phosphonates described in JP1982-30704A (JP-S57-30704A), dialkoxybenzophenones described in JP1985-26483B (JP-S60-26483B), benzoin ethers described in JP1985-26403B (JP-S60-26403B) and JP1987-81345A (JPS62-81345A), JP1989-34242B (JPH01-34242B), and the United States The following are listed: α-aminobenzophenone as described in patents 4,318,791A and EP0284561A1; p-bis(dimethylaminobenzoyl)benzene as described in JP1990-211452A (JP-H02-211452A); thiosubstituted aromatic ketones as described in JP1986-194062A (JPS61-194062A); acylphosphine sulfides as described in JP1990-9597B (JP-H02-9597B); acylphosphine as described in JP1990-9596B (JP-H02-9596B); thioxanthone as described in JP1988-61950B (JP-S63-61950B); and coumarin as described in JP1984-42864B (JP-S59-42864B). In addition, the photoinitiators described in JP2008-105379A and JP2009-114290A are also preferred.Alternatively, the photoinitiator described on pages 65-148 of "Ultraviolet Curing System" by Kato Kiyomi (Research Center Co., Ltd., published in 1989) can be used.

[0178] Particularly preferred photoinitiators include Norrish type II photoinitiators, which exhibit maximum absorption at wavelengths greater than 380 nm when measured at 23°C in one or more of the following solvents: water, ethanol, and toluene. Examples include xanthones, flavonoids, curcumin, porphyrins, anthraquinones, phenoxazines, camphorquinones, phenazines, acridines, phenothiazines, xanthonesones, thioxanthonesones, thioxanthones, acridine ketones, flavonoids, coumarins, fluorenones, quinoline, quinolones, naphthoquinones, quinolinones, arylmethanes, azo compounds, benzophenones, carotenoids, anthocyanins, phthalocyanines, dipyrrole methylene, squarine, stilbene, styryl, triazine, or anthocyanin-derived photoinitiators.

[0179] The curable composition can preferably be continuously applied to a moving porous carrier by a manufacturing unit including a curable composition application station, one or more curing stations (including an irradiation source for curing the composition), a membrane collection station, and means for moving the porous carrier from the curable composition application station to the curing station and the membrane collection station.

[0180] The curable composition application station can be located upstream of the curing station, and the curing station is located upstream of the membrane collection station.

[0181] Examples of application techniques include slot coating, glide coating, air knife coating, roll coating, screen printing, and dip coating. Depending on the technique used and the required end specifications, excess coating may need to be removed from the substrate by, for example, roll-to-roll extrusion, roll-to-blade or blade-to-roll extrusion, blade-to-blade extrusion, or by removing the coating bar. Visible light UV curing can be used at wavelengths from 100 nm to 800 nm at 40 to 2000 mJ / cm². 2 The dosage is determined. Heat curing is preferably performed at a temperature between 20°C and 100°C for 0 to 20 hours.

[0182] In some cases, additional drying may be required, which may be performed at temperatures ranging from 40°C to 200°C.

[0183] The composite membrane of the present invention can be manufactured by a variety of alternative methods, including those described in more detail below.

[0184] In the second aspect of the method of the present invention, step IV preferably includes polymerization-induced phase separation (particularly photopolymerization-induced phase separation) of the third ionic polymer and the third composition.

[0185] In one embodiment, the composite membrane includes a catalyst. The catalyst or its precursor may be contained in one or more of a first curable composition, a second curable composition, a third curable composition, and a fourth curable composition. The catalyst or its precursor may also be applied to the third ionomer (i.e., as a post-treatment step) using methods such as (but not limited to) impregnation, air knife coating, microroll coating, spraying, chemical (vapor) deposition, or physical (vapor) deposition.

[0186] Examples of suitable catalysts include metal salts, metal oxides, organometallic compounds, monomers, polymers, or copolymers. Examples include, but are not limited to, FeCl3, FeCl2, AlCl3, MgCl2, RuCl3, CrCl3, Fe(OH)3, Sn(OH)2, Sn(OH)4, SnCl2, SnCl4, SnO, SnO2, Al2O3, NiO, Zr(HPO4)2, MoS2, graphene oxide, Fe-polyvinyl alcohol composites, polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyethyleneimine (PEI), polyacrylic acid (PAA), copolymers of acrylic acid and maleic anhydride (PAAMA), and hyperbranched aliphatic polyesters. Any of these catalysts may be present at a maximum of 5% by weight (e.g., 0.001% by weight or 1% by weight) of the film weight.

[0187] The composite membranes of this invention can be used in a variety of applications, including electrodialysis and acid / alkali production. The composite membranes of this invention can also be used as bipolar membranes, particularly because they exhibit good durability and low swelling in both acidic and alkaline media, and can be produced inexpensively, quickly, and efficiently.

[0188] In an exemplary embodiment of the present invention, the composite membrane is obtained by... Figure 2 The method described schematically in the diagram is used for preparation.

[0189] The moving third porous carrier is unwound at the unwinding machine (1), impregnated with the third curable composition at the curable composition application station (2), excess of the third curable composition is removed at the metering station (3), for example by an extrusion bar, and the impregnated third porous carrier is cured at the curing station (4), thereby forming a third ionic polymer (hereinafter referred to as the “base layer”) comprising a pore network within the pores of the third porous carrier. Optionally, the solvent is removed at the drying station (5). Then, the first curable composition (also used as the fourth curable composition) and the second curable composition are simultaneously applied to the first and second sides of the base layer at the curable composition application station (6), optionally such that the first curable composition and / or the second curable composition impregnate the pore network of the third ionic polymer present in the base layer. The first and second porous carriers are unwound at the unwinding station (7) and contacted with the first and second sides of the base layer, respectively, at the lamination station (8), thereby impregnating the first and second porous carriers with the first and second curable compositions, respectively. At the curing station (9), the first and second curable compositions are cured, thereby forming a first layer a), a second layer b), and a third layer c in between. Finally, the formed composite membrane, comprising the third layer c in between the first layer a) and the second layer b), is collected at the membrane collection station (10).

[0190] In a preferred embodiment, the steps of applying the fourth curable composition to the substrate and applying the first curable composition are combined, by applying an excess of the fourth curable composition to the substrate such that the fourth curable composition impregnates the pores on one side of the substrate and forms a curable layer thereon. Then, when the fourth curable composition cures, a fourth ionomer is formed on one side of the substrate and provides a first layer a (therefore, the fourth curable composition is also used as the first curable composition to form the first layer a)).

[0191] Optionally, the method further includes a step of pretreating one or more porous supports to enhance their wetting properties. Alternatively, commercially available porous supports that have already been treated to enhance their wetting properties can be used.

[0192] To avoid ambiguity, step VIII may be used to form layer a) on one side of the substrate, and layer b) on the other side of the substrate (or on the other side of layer c) when the first curable composition of layers a) and c) is cured, and optionally layer c) may also be formed (when the curing of the first composition has not yet formed layer c).

[0193] In a preferred embodiment, the fourth curable composition is the same as the first curable composition, step VI is performed before step V, and the first porous carrier is impregnated with the first curable composition before step VI. Before step VII, the curing portion of the first curable composition in step VIII is performed, which includes curing the first curable composition (also referred to as the fourth curable composition) present in the pores of the substrate to form layer a) and partially or completely form layer c). Subsequently, the second porous carrier is impregnated with the second curable composition, and step VII is performed. Any remaining pores in the substrate are filled with the second curable composition. Finally, the curing portion of the second curable composition in step VIII is performed, thereby forming layer b) on the side of layer c) opposite to layer a).

[0194] In another preferred embodiment, the fourth curable composition is the same as the first curable composition, and step VI is performed before step V, thereby impregnating not only the pores of the substrate but also forming a layer of the first curable composition on the substrate. This is followed by the application of a first porous carrier to the first curable composition, whereby the first porous carrier is impregnated by the first curable composition. Subsequently, the curing portion of the first curable composition in step VIII is performed, which includes curing the first curable composition (also referred to as the fourth curable composition) present in the pores of the substrate, thereby forming layer a) and partially or completely forming layer c). This is followed by step VII, whereby any remaining pores in the substrate are filled with a second curable composition, and then a second porous carrier is applied to the second curable composition, whereby the second porous carrier is impregnated by the second curable composition. Finally, the curing portion of the second curable composition in step VIII is performed, thereby forming layer b) on the side of layer c) opposite to layer a).

[0195] In yet another preferred embodiment, after step III, a third porous carrier impregnated with a third curable composition is placed between transparent foils and then pressed, for example, between rollers or blades, to remove any excess of the third curable composition. After step IV, the transparent foils are removed. Further steps are preferably as described above with respect to the preferred embodiments.

[0196] In another preferred embodiment, step IV is performed under an inert atmosphere, such as nitrogen, carbon dioxide, or argon. Other steps are as described above with respect to the preferred embodiment.

[0197] The invention will now be illustrated by the following non-limiting examples, wherein all parts and percentages are by weight unless otherwise specified. Example

[0198] Table 1 Ingredients

[0199]

[0200] The synthesis of XL-A is described in Example 2 of synthesis on page 21 of EP29797448. XL-2, XL-D, and MM-M can be synthesized as follows.

[0201] PP stands for polypropylene, and PE stands for polyethylene.

[0202] Table 2. First, second and third curable compositions

[0203]

[0204] Table 3. Examples

[0205] carriers and compositions Example 1 Example 2 First porous carrier FO2223-10C <![CDATA[Solupor TM 10PO5A]]> Second porous carrier FO2223-10C <![CDATA[Solupor TM 10PO5A]]> Third porous carrier FO2223-10C <![CDATA[Solupor TM 10PO5A]]> First curable composition CC1-1 CC1-2 Second curable composition CC2 CC2 Third curable composition CC3 CC3

[0206] Preparation method 1

[0207] Step I

[0208] The first, second, and third porous carriers are as described in Table 3 above.

[0209] Step II

[0210] The first and second curable compositions are prepared by mixing the components shown in Table 2 above. The first curable composition is also used as the fourth curable composition. The third curable composition is prepared by mixing the components shown in Table 2 above.

[0211] Step III

[0212] A 100 μm thick third curable composition layer is applied to a PET foil using a Meyer rod. A third porous carrier (FO2223-10C) is applied to the third curable composition layer, thereby impregnating it with the third curable composition. A second PET foil is then applied to the impregnated third porous carrier to provide an encapsulation of the impregnated third porous carrier between the two foils. All air is gently extruded from the porous carrier using a roller.

[0213] Step IV

[0214] The encapsulation of a third porous carrier impregnated between two foils was irradiated using a Light Hammer LH10 from Fusion UV Systems, equipped with a D-shaped bulb operating at 5 m / min and 60% intensity, to cure the third curable composition present in the third porous carrier. After curing, the PET foils were removed, and the cured product was allowed to dry in air at room temperature to obtain the base layer (i.e., the third porous carrier containing a third ionic polymer with a porous network).

[0215] The substrate was impregnated in a catalyst solution containing 1.35 wt% tin(II) chloride in a slightly acidic aqueous solution and dried at room temperature. Subsequently, the substrate was impregnated in a 0.12 N NaOH solution to precipitate the catalyst and dried at room temperature.

[0216] Steps V and VI

[0217] The first curable composition was applied to a PET foil using a 100 μm Meyer rod. A first porous carrier was then applied to the first curable composition layer on the PET, thereby impregnating the first porous carrier with the first curable composition. After 5 seconds, excess first curable composition was removed from the first porous carrier using a 24 μm Meyer rod to obtain a first curable composition layer approximately 24 μm thick on the surface of the impregnated first porous carrier. The substrate prepared in step IV above was placed on top of the first curable composition layer, thus impregnating the substrate with the first curable composition to obtain a substrate-first porous carrier composite in which the first curable monomer is contained in the pores of both the first porous carrier and the third ionomer.

[0218] Step VIII (partial)

[0219] The prepared substrate-first porous carrier composite was irradiated on one side (the side with the substrate and first porous carrier) using a Light Hammer LH10 from Fusion UV Systems, the Light Hammer LH10 being equipped with a D-shaped bulb operating at 50% intensity at a speed of 5 m / min. The resulting cured film was a laminate of layers a) and c), wherein the pores of the third ionomer were filled with the cured first curable composition.

[0220] Step VII

[0221] Using a Meyer bar, a 100 μm layer of the second curable composition is applied to the laminate of layers a) and c) on the side opposite to layer a), and a second porous carrier is applied to the second curable composition layer. After 5 seconds, excess second curable composition is removed using a 4 μm Meyer bar.

[0222] Step VIII (partial)

[0223] The product from step VII was irradiated from both sides using a Light Hammer LH10 from Fusion UV Systems, which is equipped with a D-shaped bulb operating at 50% intensity at a speed of 5 m / min, to cure the second curable composition. Finally, the PET foil was removed to obtain a bipolar composite film of the first aspect of the invention, comprising a first layer a), a second layer b), and a third layer c) between the first layer a) and the second layer b).

[0224] Preparation method 2

[0225] Steps I and II are performed as described in method 1 above.

[0226] Step III

[0227] A 60 μm thick layer of the third curable composition is applied to the third porous carrier laid on a PET foil using a Meyer rod. Excess coating is removed using a 4 μm Meyer rod to ensure the third porous carrier is impregnated with the third curable composition. A second PET foil is applied to the impregnated third porous carrier to provide an encapsulation of the impregnated third porous carrier between the two foils. All air is gently expelled from the porous carrier using a roller.

[0228] Step IV

[0229] The encapsulation of a third porous carrier impregnated between two foils was irradiated using a Light Hammer LH10 from Fusion UV Systems, which was equipped with a D-shaped bulb operating at 60% intensity at a speed of 5 m / min. After curing, the PET foils were removed, and the cured product was allowed to air dry at room temperature to obtain the base layer (i.e., a third porous carrier containing a third ionic polymer with a porous network).

[0230] The substrate was impregnated in a catalyst solution containing 1.35 wt% tin(II) chloride in a slightly acidic aqueous solution and dried at room temperature. Subsequently, the substrate was impregnated in a 0.12 N NaOH solution to precipitate the catalyst and dried at room temperature.

[0231] Steps V and VI

[0232] The first curable composition is applied to a first porous support laid on a PET foil using a 60 μm Meyer rod. Excess first curable composition is removed using a 4 μm rod, thereby completely impregnating the first porous support with the first curable composition. A second layer of the first curable composition is applied to the impregnated first porous support using a 24 μm Meyer rod, leaving an approximately 24 μm layer of the first curable composition on the surface of the impregnated first porous support. The catalyst-containing base layer produced in step IV above is placed on the first curable composition layer, thus impregnating the base layer with the first curable composition to obtain a base layer-first porous support composite in which the first curable monomer is contained in the pores of both the first porous support and the third ionomer.

[0233] Step VIII (partial)

[0234] The substrate-first porous carrier composite was irradiated on one side (the side with the first porous carrier) using a Light Hammer LH10 from Fusion UV Systems, which was equipped with a D-shaped bulb operating at 50% intensity at a speed of 5 m / min. The resulting cured film was a laminate of layers a) and c), wherein the pores of the third ionomer were filled with the cured first curable composition.

[0235] Step VII

[0236] The second curable composition was applied to the second porous carrier using a 60 μm Meyer rod to obtain an impregnated second porous carrier. The impregnated second porous carrier was then applied to the laminate of layers a) and c) on the opposite side of layer a). After 5 seconds, excess second curable composition was removed using a 4 μm Meyer rod.

[0237] Step VIII (partial)

[0238] The product from step VII was irradiated from both sides using a Light Hammer LH10 from Fusion UV Systems, which is equipped with a D-shaped bulb operating at 50% intensity at a speed of 5 m / min, to cure the second curable composition. Finally, the PET foil was removed to obtain a bipolar composite film of the first aspect of the invention, comprising a first layer a), a second layer b), and a third layer c) between the first layer a) and the second layer b).

[0239] The substrates prepared using method 1 or method 2 were analyzed to determine the average flow orifice (MFP) size, and the results are shown in Table 4 below.

[0240] Using Porolux TM A porosimeter was used to determine the average flow rate and pore size of pores in the third ionomer (sample with a diameter of 18.5 mm) present in the substrate prepared using method 1 or method 2. The substrate sample was tested using a "Porefill" method. TM "Prewet the fluid for about 15 seconds and place it in the sample holder. During the measurement, use increased N2 pressure (up to 6 bar) to purge the vent until all fluid is drained."

[0241] Table 4

[0242] nature Method 1 Method 2 MFP dimensions (μm) 0.965 1.041 Minimum pore size (μm) 0.355 0.434

[0243] The difference between the two methods is believed to be due to differences in the experiments.

[0244] Example 1 was prepared using method 1, and Example 2 was prepared using method 2.

[0245] Characterization of composite membranes

[0246] The volume ratio is the ratio of the volume of the third ionic polymer to the volume of the fourth ionic polymer in layer c), where in these embodiments the fourth ionic polymer is the same as the first ionic polymer. The volume ratio was determined by embedding the sample from Example 1 in resin and cutting thin sections using a microtome. These sections were analyzed by atomic force microscopy (AFM) equipped with an infrared probe. Line spectra were recorded every 3 μm in the 80 μm range, and principal component analysis was performed using the infrared spectroscopy. The resulting images showed that the third and fourth ionic polymers were discrete polymers, with the third ionic polymer identified in green and the fourth in blue. The third and fourth ionic polymers were observed to form a co-continuous network in layer c).

[0247] The ratio of these two polymers (i.e., the volume ratio of the third ionic polymer to the fourth ionic polymer in the third layer c) is estimated by their color, and this ratio is given in Table 5 below.

[0248] The electrochemical properties and bipolar characteristics of the bipolar composite membranes of Examples 1 and 2 were compared with those of commercially available bipolar membranes (BPMs) by measuring their so-called IU curves, and the voltage at a specific current density was derived from the IU curves. This evaluation showed that at 800 A / cm... 2 At the specified current density, the voltage of the bipolar composite membrane of this invention is lower than that of commercially available BPMs. The results are shown in Table 5 below.

[0249] Table 5

[0250] sample <![CDATA[800A / m 2 Voltage (V) volume ratio Commercially available BPM 0.98 nd Example 1 0.89 0.44 / 0.56 Example 2 0.91 nd

[0251] nd indicates not measured

[0252] Synthesis of anionic monomers, crosslinking agents and their precursors

[0253] Cl-SS

[0254]

[0255] In a double-walled reactor actively cooled to 5°C, thionyl chloride (109 mL, 178.46 g, 1.5 mol, 3 molar equivalent) was added dropwise to a DMF (300 mL) solution of lithium 4-vinylbenzenesulfonate (95.08 g, 0.500 mol, 1 molar equivalent) and 4OH-TEMPO (50 mg, 500 ppm). After the addition was complete, the solution was slowly heated to room temperature and stirred for 16 hours. The reaction mixture was then poured into 1 L of cold 1M KCl in a separatory funnel. The bottom layer was removed and dissolved in 500 mL of diethyl ether. The solution was washed with 1M KCl- solution (300 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated under vacuum to obtain a yellow oil. The crude product (CL-SS) was used without further purification in the next step. Typical yield was 89.5 g (88%). HPLC-MS purity >98%; 1 H-NMR: <2% DMF by weight, 0% diethyl ether.

[0256] Cl-DVBS

[0257]

[0258] In a double-walled reactor actively cooled to 5°C, thionyl chloride (75 mL, 123.1 g, 1.034 mol, 3 molar equivalent) was added dropwise to a solution of sodium divinylbenzenesulfonate (80 g, 0.345 mol, 1 molar equivalent) and 4OH-TEMPO (50 mg, 500 ppm) in DMF (300 mL). After the addition was complete, the solution was slowly heated to room temperature and stirred for 16 hours. The reaction mixture was then poured into 1 L of cold 1M KCl in a separatory funnel. The bottom layer was removed and dissolved in 500 mL of diethyl ether. The solution was washed with 1M KCl- solution (300 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated under vacuum to obtain a yellow oil. The crude product (Cl-DVBS) was ready for use in the next step without further purification. Typical yield was 62 g (79%). HPLC-MS purity >98%; 1 H-NMR: <2% DMF by weight, 0% diethyl ether.

[0259] NH2-SS

[0260]

[0261] In a double-walled reactor actively cooled to 5°C, thionyl chloride (109 mL, 178.46 g, 1.5 mol, 3 molar equivalent) was added dropwise to a DMF (300 mL) solution of lithium 4-vinylbenzenesulfonate (95.08 g, 0.500 mol, 1 molar equivalent) and 4OH-TEMPO (50 mg, 500 ppm). After the addition was complete, the solution was slowly heated to room temperature and stirred for 16 hours. The reaction mixture was then poured into 1 L of cold 1M KCl in a separatory funnel. The bottom layer was removed, and the mixture was added dropwise in a 25% ammonium hydroxide aqueous solution (250 mL, 3.67 mol, 15 molar equivalent) and 4OH-TEMPO (50 mg, 500 ppm) in a double-walled reactor actively cooled to 5°C. After the addition was complete, the solution was stirred for 1 hour. The solution was then heated to room temperature and stirred for 1 hour. The reaction mixture was then cooled back to 5°C, the product was filtered off, and washed with 50 mL of cold water. The product (NH2-SS) was dried under vacuum overnight at 30°C and used without further purification. Typical yield was 66.8 g (73%). HPLC-MS purity >95%.

[0262] Synthesis of XL-D

[0263]

[0264] Before synthesis, methanesulfonamide was dried overnight in a vacuum oven (30°C, vacuum). LiH (1.53 g, 0.192 mol, 2.2 mol equivalent) as solid was immediately added to a THF (100 mL) solution of dried methanesulfonamide (8.32 g, 0.087 mol, 1 mol equivalent) and 4OH-TEMPO (30 mg, 500 ppm). The reaction mixture was stirred at room temperature for 30 minutes. Then, a THF (50 mL) solution of Cl-DVBS (20 g, 0.087 mol, 1 mol equivalent) was added to the reaction mixture. After addition, the reaction mixture was heated to 60°C (water bath temperature). Two days later, the reaction mixture was filtered with diatomaceous earth to remove excess LiH. The filtrate was concentrated under vacuum to obtain a pale yellow foam. The resulting foam was dissolved in 500 mL of ethyl acetate. Diatomaceous earth was added, and the resulting slurry was stirred for 5 minutes. The diatomaceous earth was then filtered off, and the mixture was washed with 100 mL of ethyl acetate. This diatomaceous earth procedure was then repeated. The solvent was then evaporated under vacuum, and the resulting white foam was washed overnight with 500 mL of diethyl ether. The resulting white powder was filtered off and dried in a vacuum oven at 30 °C for 16 h, yielding a hygroscopic white solid. A typical yield was 15.5 g (60%). HPLC-MS purity >95%. 1H-NMR: <3% by weight residual solvent; 2% by weight divinylbenzenesulfonate; ICP-OES: 24-30 g Li / kg product.

[0265] Synthesis of XL-2

[0266]

[0267] Prior to synthesis, styrene sulfonamide (NH2-SS) was dried overnight in a vacuum oven (30°C, vacuum). LiH (1.50 g, 0.189 mol, 4.2 mol equivalent) as solid was immediately added to a THF (100 mL) solution of the dried styrene sulfonamide (16.90 g, 0.092 mol, 2.05 mol equivalent) and 4OH-TEMPO (30 mg, 500 ppm). The reaction mixture was stirred at room temperature for 30 minutes. Then, a THF (50 mL) solution of 1,3-benzene disulfonyl chloride (12.38 g, 0.045 mol, 1 mol equivalent) was added to the reaction mixture. After addition, the reaction mixture was heated to 60°C (water bath temperature). After 2 days, the reaction mixture was filtered through diatomaceous earth to remove excess LiH. The filtrate was concentrated under vacuum to obtain a pale yellow foam. The resulting foam was dissolved in 500 mL of ethyl acetate. Diatomaceous earth was added, and the resulting slurry was stirred for 5 minutes. The diatomaceous earth was then filtered off and the sample was washed with 100 mL of ethyl acetate. This diatomaceous earth procedure was then repeated. The solvent was then evaporated under vacuum, and the resulting white foam was washed overnight with 500 mL of diethyl ether. The resulting white powder was filtered off and dried in a vacuum oven at 30 °C for 16 h to produce a hygroscopic white solid. A typical yield was 14.5 g (54%). HPLC-MS purity >96%. 1 H-NMR: <2 wt% residual solvent; <2 wt% styrene sulfonamide; ICP-OES: 35-40 g Li / kg product.

[0268] Synthesis of MM-M

[0269]

[0270] Before synthesis, methanesulfonamide was dried overnight in a vacuum oven at 30°C. LiH (0.300 mol, 3 molar equivalents) as solid was immediately added to a THF (100 mL) solution of dried methanesulfonamide (0.100 mol, 1 molar equivalent) and 4OH-TEMPO (30 mg, 500 ppm). The reaction mixture was stirred at room temperature for 30 minutes. Then, a THF (50 mL) solution of vinylbenzylsulfonyl chloride (Cl-SS) (0.100 mol, 1 molar equivalent) was added, and the reaction mixture was heated to 60°C (water bath temperature) for 16 hours. The resulting solution was filtered through diatomaceous earth, and the resulting foam was dissolved in 500 mL of ethyl acetate. Diatomaceous earth was added, and the resulting slurry was stirred for 5 minutes. The diatomaceous earth was then filtered off and washed with 100 mL of ethyl acetate. The solvent was then evaporated under vacuum, and the resulting white foam was pulverized overnight with 500 mL of diethyl ether. The product was collected by filtration and separated into a white hygroscopic powder (yield 80%, purity >94%).

Claims

1. A composite membrane comprising: a) A first layer comprising a first porous support and a first ionic polymer present in the pores of the first porous support; b) A second layer comprising a second porous support and a second ionic polymer present in the pores of the second porous support; c) A third layer comprising a third porous support, a third ionic polymer, and a fourth ionic polymer, wherein the third ionic polymer is present in the pores of the third porous support; in: (i) One of the first ionic polymer and the second ionic polymer is a cationic polymer, and the other is an anionic polymer; (ii) The third layer is located between the first layer and the second layer; (iii) The third ionic polymer comprises a porous network, and the fourth ionic polymer is present within the pores of the third ionic polymer; and (iv) One of the third ionic polymer and the fourth ionic polymer is a cationic polymer, and the other is an anionic polymer.

2. The composite membrane of claim 1, wherein the third ionic polymer is obtained by a method comprising phase separation of the third ionic polymer from the composition used to prepare the third ionic polymer.

3. The composite membrane of claim 2, wherein the phase separation is polymerization-induced phase separation.

4. The composite membrane according to any one of claims 1 to 3, wherein the pore network comprises the first ionic polymer and the second ionic polymer, such that the first ionic polymer acts as a fourth ionic polymer to partially fill the pores of the third ionic polymer, and the second ionic polymer fills the remaining pores.

5. The composite membrane according to any one of claims 1 to 3, wherein the third ionic polymer has the same charge as the second ionic polymer.

6. The composite membrane according to any one of claims 1 to 3, wherein the third ionic polymer and the fourth ionic polymer present in the third layer form a co-continuous network, wherein the third ionic polymer and the fourth ionic polymer are discrete and non-uniformly mixed with each other.

7. The composite membrane according to any one of claims 1 to 3, wherein the first layer, the second layer and the third layer each independently have an average thickness of 10 μm to 200 μm.

8. The composite membrane according to any one of claims 1 to 3, comprising a first interface between the first layer and the third layer and a second interface between the third layer and the second layer, wherein the first interface and the second interface are uninterrupted, and there are no gaps and / or spaces between the first layer and the third layer, and no gaps and / or spaces between the third layer and the second layer.

9. The composite membrane according to any one of claims 1 to 3, comprising a third interface between the third ionic polymer and the fourth ionic polymer, the interface being uninterrupted and having no gaps and / or spaces between the third ionic polymer and the fourth ionic polymer.

10. The composite film according to any one of claims 1 to 3, wherein the first ionomer is obtained by a method comprising curing a first curable composition, the first curable composition comprising: (a1) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group; (b1) 1 to 88% by weight of a curable compound containing at least two olefinic unsaturated groups and ionic groups; (c1) 0 to 10% by weight of a free radical initiator; and (d1) 0 to 55% by weight of solvent.

11. The composite film of claim 10, wherein the second ionomer is obtained by a method comprising curing a second curable composition, the second curable composition comprising: (a2) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group having an opposite charge to the curable compound present in the first curable composition; (b2) 1 to 88% by weight of a curable compound containing at least two olefinic unsaturated groups and ionic groups; (c2) 0 to 10% by weight of a free radical initiator; and (d2) 0 to 55% by weight of solvent.

12. The composite film according to any one of claims 1 to 3, wherein the third ionomer is obtained by a method comprising curing a third curable composition, the third curable composition comprising: (a3) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group; (b3) 1 to 70% by weight of a curable compound containing at least two olefinic unsaturated groups and ionic groups; (c3) 0 to 10% by weight of a free radical initiator; and (d3) 20 to 98% by weight of solvent.

13. The composite membrane of claim 12, wherein the fourth ionomer is obtained by a method comprising curing a fourth curable composition, the fourth curable composition comprising: (a4) 0 to 60% by weight of a curable compound having an olefinic unsaturated group and an ionic group having an opposite charge to the curable compound present in the third curable composition; (b4) 1 to 88% by weight of a curable compound containing at least two olefinic unsaturated groups and ionic groups; (c4) 0 to 10% by weight of a free radical initiator; and (d4) 0 to 55% by weight of solvent.

14. The composite membrane according to any one of claims 1 to 3, wherein it is a composite bipolar membrane.

15. The composite membrane according to any one of claims 1 to 3, wherein the volume ratio of the third ionic polymer to the fourth ionic polymer is 0.1 to 0.

9.

16. A method for preparing a composite membrane, comprising the following steps: I. Provide a first porous support, a second porous support, and a third porous support; II. Provides a first curable composition comprising a curable compound, a second curable composition comprising a curable compound having an opposite charge to the curable compound present in the first curable composition, a third curable composition comprising a curable compound, and a fourth curable composition comprising a curable compound having an opposite charge to the curable compound present in the third curable composition; III. Impregnate the third porous carrier with the third curable composition; IV. Curing the third curable composition present in the third porous carrier to form a base layer comprising the third porous carrier and a third ionic polymer comprising a pore network; V. Impregnate the porous network of the third ionomer with the fourth curable composition; VI. Bring the first curable composition into contact with a first side of the substrate; VII. Bring the second curable composition into contact with the second side of the substrate; and VIII. The first curable composition, the second curable composition, and the fourth curable composition are cured in any order or simultaneously to form the first ionic polymer, the second ionic polymer, and the fourth ionic polymer, respectively; in: (a) When the first curable composition is cured, the first curable composition includes the first porous carrier; (b) When the second curable composition is cured, the second curable composition includes the second porous carrier; (c) One of the first curable composition and the second curable composition comprises a curable compound having an olefinic unsaturated group and an anionic group, while the other comprises a curable compound having an olefinic unsaturated group and a cationic group; and (d) One of the third curable composition and the fourth curable composition comprises a curable compound having an olefinic unsaturated group and an anionic group, while the other comprises a curable compound having an olefinic unsaturated group and a cationic group.

17. The method of claim 16, wherein when the first curable composition is applied to a first side of the substrate, the first curable composition comprises the first porous carrier.

18. The method of claim 16, wherein the first porous carrier is applied to the first curable composition after the first curable composition has been applied to a first side of the substrate.

19. The method of any one of claims 16 to 18, wherein when the second curable composition is applied to a second side of the substrate, the second curable composition comprises the second porous carrier.

20. The method of any one of claims 16 to 18, wherein the second porous carrier is applied to the second curable composition after the second curable composition has been applied to the second side of the substrate.

21. The method of any one of claims 16 to 18, wherein the first curable composition of the first porous carrier is cured prior to the curing of the second composition comprising the second porous carrier.

22. The method of any one of claims 16 to 18, wherein a first curable composition comprising the first porous carrier and a second composition comprising the second porous carrier are simultaneously cured.

23. The method of any one of claims 16 to 18, wherein the first curable composition is the same as the fourth curable composition.

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