membrane

Abstract

Monomer a of Formula I: AR 1 -(CH2) n -N + (R a R b )-(CH2) n -AR 2 , X - wherein each n is independently 1 or 2; (1) R a and R b are each independently optionally substituted C 1~3 alkyl group or optionally substituted C 2~3 (2) R is an alkenyl group; a and R b form an optionally substituted five- or six-membered ring together with the positively charged nitrogen atom to which they are attached; (3) R a and R b One of them is an arbitrarily replaceable C 1~3 alkyl group or optionally substituted C 2~3 R is an alkenyl group a and R b The other is AR 1 -(CH2) n -N + together with the R group to form an optionally substituted 5- or 6-membered ring; or (4) R a is AR 1 -(CH2) n -N + R 1 and R 2 form an optionally substituted 5- or 6-membered ring together. b is N + -(CH2) n -AR 2 together with the group X to form an optionally substituted 5- or 6-membered ring; - is the anion; AR 1 and AR 2 each independently contains an aromatic group; (1') AR 1 and AR 2 (2') monomer a of formula I contains at least two curable ethylenically unsaturated groups; and (3') the molar fraction of component a relative to all curable components of the curable composition is at least 0.90.

Description

[Technical Field]

[0001] The present invention relates to ion exchange membranes, in particular anion exchange membranes (AEMs), their preparation process and their use. [Background technology]

[0002] Ion exchange membranes are used in electrodialysis, electrolysis, acid and base production, and many other processes. Typically, the transport of ions through the membrane occurs under the influence of a driving force, such as a potential gradient.

[0003] Some ion exchange membranes include a porous support, which provides mechanical strength. Such membranes are often called "composite membranes" because of the presence of both an ionic-charged polymer that discriminates between oppositely charged ions and a porous support that provides mechanical strength.

[0004] BPM is commonly used to generate acids and bases, for example in a process called bipolar electrodialysis (BPED). BPM has both a cationic or anion exchange layer (AEL) and an anionic or cation exchange layer (CEL), and therefore has both negatively and positively charged layers.

[0005] In the BPED process, acids and bases are generated at the boundary of the BPM by the water dissociation reaction (WDR). + and OH -The ions pass through the corresponding ion exchange layers toward the cathode and anode, respectively. The BPED process is carried out in a bipolar electrodialysis stack, which contains monopolar anion exchange and monopolar cation exchange membranes in addition to a bipolar membrane. In a bipolar electrodialysis stack, the monopolar cation and anion exchange membranes are responsible for selectively separating salt ions in the feed stream according to their charge. The salt anions then combine with H+ formed by the WDR to form acids, and the salt cations combine with OH- to form bases. For example, if NaCl is used in the feed stream, the monopolar membrane will separate Cl - From Na + By separating the two, NaOH and HCl are formed.

[0006] To generate high concentrations of acids and bases, it is important that the monopolar membrane has very high pH stability and durability (high pH stability and durability lead to a long membrane life). High efficiency of the acid and base generation process is also desirable. This is because the membrane has very high permselectivity, which allows for the H + and OH - It is necessary to prevent ions from reaching the wrong channel and recombining, leading to product loss. Especially for anion exchange membranes, it is difficult to achieve high proton blocking capacity at high concentrations due to the small size of protons. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide an anion exchange membrane that is mechanically strong, has high stability at very low pH values, and has high permselectivity at high acid concentrations. DETAILED DESCRIPTION OF THE INVENTION

[0008] According to a first aspect of the present invention, there is provided an anion exchange membrane obtainable by curing a curable composition, the curable composition comprising: (a) Monomer (a) of formula (I) AR 1 -(CH2) n -N + (R a R b )-(CH2) n -AR 2 , X - Formula (I) Including, During the ceremony, each n independently has a value of 1 or 2; (i)R a and R b each independently represents an optionally substituted C 1~3 alkyl group or optionally substituted C 2~3 is an alkenyl group; or (ii)R a and R b together with the positively charged nitrogen atom to which they are attached form an optionally substituted 5- or 6-membered ring; or (iii)R a and R b one of which is optionally substituted C 1~3 alkyl group or optionally substituted C 2~3 is an alkenyl group, R a and R b The other is the formula AR 1 -(CH2) n -N + together with the group: (iv)R a is the formula AR 1 -(CH2) n -N + together with the group R b is the formula N + -(CH2) n -AR 2 together with the group form an optionally substituted 5- or 6-membered ring; X - is an anion; AR 1 and A.R. 2 each independently comprises an aromatic group; (I)AR 1 and A.R. 2 at least one of contains a curable ethylenically unsaturated group; (II) monomer (a) of formula (I) contains at least two curable ethylenically unsaturated groups; (III) The above anion exchange membrane is provided, wherein the molar fraction of component (a) relative to all curable components of the curable composition is at least 0.90.

[0009] In this document (including the claims), the verb "comprise" and its conjugations are used in their open-ended sense to mean that items that follow the word are included, but that items not specifically mentioned are not excluded. In addition, when an element is referred to by the indefinite article "a" or "an," it does not exclude the possibility that more than one of the element is present, unless the context clearly requires that only one or one of the element be present. Thus, the indefinite article "a" or "an" typically means "at least one."

[0010] Preferably, monomer (a) contains at least two curable ethylenically unsaturated groups, more preferably two and only two curable ethylenically unsaturated groups. Preferably, the curable ethylenically unsaturated groups are AR 1 and / or A.R. 2 In a preferred embodiment, AR 1 and A.R. 2 each contain one or only one curable ethylenically unsaturated group, and monomer (a) has a total of two curable ethylenically unsaturated groups.

[0011] Curable ethylenically unsaturated groups can react with other curable ethylenically unsaturated groups to form covalent bonds therewith, for example, when heated and / or irradiated with light (e.g., ultraviolet light) or an electron beam.

[0012] Preferred curable ethylenically unsaturated groups are vinyl and allyl groups, most preferably vinyl groups. The vinyl group (CH=CH-) is non-acrylic, i.e., the vinyl group is not bonded to a (C=O)O- or (C=O)NH- group.

[0013] The positively charged nitrogen atom (N + ) is a non-aromatic system, i.e., it is not part of an aromatic heterocycle. Preferably, the anion X - does not react with other components of the curable composition, i.e., X - is inactive. X - Preferred anions represented by X include hydroxide, fluoride, chloride, bromide, iodide, nitrate, thiocyanate, hexafluoroborate, methanesulfonate, trifluoromethanesulfonate, formate, and acetate. - is a chloride anion because it can provide a monomer of formula (I) with excellent solubility without dramatically increasing the molecular weight of the monomer (a) of formula (I).

[0014] Preferably, each n independently has a value of 1. In a particularly preferred embodiment, both n's have a value of 1. In one embodiment, R a and R b each independently represents an optionally substituted C 1~3 alkyl groups (e.g., methyl, ethyl, propyl, or isopropyl) and optionally substituted C 2~3 Alkenyl groups (e.g., -CH=CH2 or -CH2CH=CH2) are selected.

[0015] In another embodiment, R a and R b together with the positively charged nitrogen atom to which they are attached form an optionally substituted 5- or 6-membered ring, for example an optionally substituted pyrrolidinium, pyrrolinium, imidazolinium, piperidinium or morpholinium ring.

[0016] In another embodiment, R a and R b one of which is optionally substituted C 1~3 alkyl group or optionally substituted C 2~3 is an alkenyl group, R a and R b The other is the formula AR 1 -(CH2) n -N + A group of formula (wherein AR 1 and n is as defined above) together form an optionally substituted 5- or 6-membered ring, for example an optionally substituted pyrrolidinium, pyrrolinium, piperidinium or morpholinium ring, in each case having an aromatic ring (e.g. a benzene ring) fused thereto (preferably with two or more, preferably one, curable ethylenically unsaturated group attached to the benzene ring).

[0017] In another embodiment, R a is the formula AR 1 -(CH2) n -N + A group of formula (wherein AR 1 and n is as defined above) together form an optionally substituted 5- or 6-membered ring, R b is the formula N + -(CH2) n -AR 2 A group of formula (wherein AR 2 and n is as defined above) together form an optionally substituted 5- or 6-membered ring.

[0018] Preferred optionally substituted 5- or 6-membered rings are as defined above (an example is a 6-azoniaspiro[5.5]undecylene ring). Preferred optional substituents are curable ethylenically unsaturated groups (as described above and are preferred).

[0019] Preferably, AR 1 and A.R. 2 Each independently contains a phenyl or styrenyl group. More preferably, AR 1 and A.R. 2 are both styrenyl groups. In a preferred embodiment, the monomer (a) has the formula (II):

[0020] [ka]

[0021] wherein R a , R b and X - is as defined above. Component (a) may optionally contain one or more monomers (a) of formula (I) (more preferably formula (II)), for example, AR 1 and / or A.R. 2 It may also comprise a mixture of isomers in which the curable unsaturated groups are present in different positions (eg, ortho, meta and / or para positions).

[0022] Examples of monomers that can be used as the monomer (a) include the following compounds AXL-1 to AX-11.

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] The curable composition preferably contains 50 to 90 wt % of component (a), more preferably 65 to 85 wt %, and especially 69 to 83 wt % of component (a). In one embodiment, the anion exchange membrane according to the first aspect of the present invention comprises (typically as a result of incomplete curing when the membrane is formed) at least 1 ppm of monomer (a), preferably at least 10 ppm, in particular at least 100 ppm of monomer (a). Preferably, the anion exchange membrane comprises less than 20,000 ppm of monomer (a), more preferably less than 10,000 ppm of monomer (a).

[0027] The curable composition optionally further comprises, as component (b), a monomer comprising a group having a cationic charge and one or only one curable ethylenically unsaturated group. Preferably, the curable composition does not comprise component (b), or the composition comprises a small amount of component (b), for example, the curable composition preferably comprises 0 to 10 wt % of component (b), more preferably 0 to 7 wt % of component (b).

[0028] In monomer (b), the group having a cationic charge is preferably a quaternary ammonium group. The one and only curable ethylenically unsaturated group present in monomer (b) is preferably a vinyl or allyl group, more preferably a vinyl group.

[0029] Component (b) may comprise one or more than one monomer (b) containing a group with a cationic charge and one or only one curable ethylenically unsaturated group. In one embodiment, component (b) has the formula (SM), where R 1 , R 2 and R 3 each independently represents an alkyl group or an aryl group, or R 1 , R 2and R 3 two or three of these, together with the positively charged nitrogen atom to which they are attached, form an optionally substituted 5- or 6-membered ring; n3 represents an integer of 1 to 3; X3 - represents an anion, preferably a chloride ion, a bromide ion, an iodide ion or a hydroxide ion.

[0030] [ka]

[0031] Examples of component (b) of formula (SM) include the following compounds:

[0032] [ka]

[0033] The above components can be prepared, for example, as described in US2016177006. The curable composition optionally further comprises a radical initiator as component (c). Preferred radical initiators include thermal initiators, photoinitiators, and combinations thereof.

[0034] The curable composition preferably comprises 0 to 10 wt % of a radical initiator, more preferably 0 to 3 wt % of a radical initiator. If the curable composition is to be cured using ultraviolet light, visible light, or thermally, the curable composition preferably comprises 0.001 to 2 wt %, especially 0.005 to 1.5 wt %, of a radical initiator.

[0035] Examples of suitable thermal initiators that can be used as component (c) include 2,2'-azobis(2-methylpropionitrile) (AIBN), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), nitrile), 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-methylpropionamide) 2,2'-Azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 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-methylpropionamidine]hydrate, 2,2'-Azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}dihydrate Examples of suitable azobis include 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(1-imino-1-pyrrolidino-2-ethylpropane) dihydrochloride, 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].

[0036] Examples of suitable photoinitiators that may be included as component (c) in the curable composition include aromatic ketones, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, boric acid compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds. Preferred examples of aromatic ketones, acylphosphine oxide compounds, and thio compounds include compounds having a benzophenone skeleton or thioxanthone skeleton described in "RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY," pp. 77-117 (1993).More preferred examples thereof include alpha-thiobenzophenone compounds described in JP1972-6416B (JP 47-006416), benzoin ether compounds described in JP1972-3981B (JP 47-003981), alpha-substituted benzoin compounds described in JP1972-22326B (JP 47-022326), and alpha-substituted benzoin compounds described in JP1972-23664B (JP 47-022326). benzoin derivatives described in JP1982-30704A (JP 57-030704 A), aroylphosphonic acid esters described in JP1982-30704A (JP 57-030704 B), dialkoxybenzophenones described in JP1985-26483B (JP 60-026483 B), and benzoin derivatives described in JP1985-26403B (JP 60-026403 B) and JP1987-81345A (JP 62-081345 B). Benzoin ethers, alpha-aminobenzophenones described in JP1989-34242B (JP-B 01-034242), US4,318,791A, and EP0284561A1, p-di(dimethylaminobenzoyl)benzene described in JP1990-211452A (JP-A 02-211452), thio-substituted benzoin ethers described in JP1986-194062A (JP-A 61-194062), and the like. Examples of suitable initiators include substituted aromatic ketones, acylphosphine sulfides described in JP1990-9597B (JP Patent Publication No. 02-009597), acylphosphines described in JP1990-9596B (JP Patent Publication No. 02-009596), thioxanthones described in JP1988-61950B (JP Patent Publication No. 63-061950), and coumarins described in JP1984-42864B (JP Patent Publication No. 59-042864). In addition, photoinitiators described in JP2008-105379A and JP2009-114290A are also preferred. In addition, photoinitiators described in "Ultraviolet Curing System" by Kato Kiyomi, pages 65-148 (published by Research Center Co., Ltd. in 1989) can also be used.

[0037] Particularly preferred photoinitiators include Norrish Type II photoinitiators having an absorption maximum at a wavelength greater than 380 nm when measured in one or more of water, ethanol, and toluene at a temperature of 23° C. Examples include photoinitiators derived from xanthenes, flavins, curcumins, porphyrins, anthraquinones, phenoxazines, camphorquinones, phenazines, acridines, phenothiazines, xantithones, thioxantithones, thioxanthenes, acridones, flavones, coumarins, fluorenones, quinolines, quinolones, naphthoquinones, quinolinones, arylmethanes, azos, benzophenones, carotenoids, cyanines, phthalocyanines, dipyrrines, squarines, stilbenes, styryls, triazines, or anthocyanins.

[0038] Optionally, the curable composition further comprises a monomer that does not contain a group with a cationic charge, and preferably further comprises a monomer that contains at least two curable ethylenically unsaturated groups as component (d).

[0039] Preferably, the curable composition contains 0 to 5 wt % of component (d), and more preferably, the curable composition does not contain component (d). The curable composition preferably further comprises a solvent as component (e). The solvent is preferably an inert solvent. The inert solvent does not react with any of the other components of the curable composition. In a preferred embodiment, component (e) comprises water and optionally an organic solvent, particularly when some or all of the organic solvent is water-miscible. Water is useful for dissolving components (a) and (b), and optionally also component (c), and the organic solvent is also useful for dissolving any organic components present in the curable composition.

[0040] Component (e) is useful for reducing the viscosity and / or surface tension of the curable composition. In a preferred embodiment, the curable composition comprises 10 to 40 wt %, especially 20 to 30 wt %, of component (e).

[0041] Examples of inert solvents that can be used as or in component (e) include water, alcohol-based solvents, ether-based solvents, amide-based solvents, ketone-based solvents, sulfoxide-based solvents, sulfone-based solvents, nitrile-based solvents, and organophosphorus-based solvents. Examples of alcohol-based solvents that can be used as or in component (e) (especially in combination with water) include methanol, ethanol, isopropanol, n-propanol, n-butanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and mixtures containing two or more thereof. Additionally, preferred inert organic solvents that can be used in component (e) include dimethyl sulfoxide, dimethylimidazolidinone, sulfolane, N-methylpyrrolidone, dimethylformamide, acetonitrile, acetone, 1,4-dioxane, 1,3-dioxolane, tetramethylurea, hexamethylphosphoramide, hexamethylphosphorotriamide, pyridine, propionitrile, butanone, cyclohexanone, tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, ethylene glycol diacetate, cyclopentyl methyl ether, methyl ethyl ketone, ethyl acetate, y-butyrolactone, and mixtures containing two or more thereof.

[0042] The molar fraction of component (a) relative to all curable compounds present in the curable composition is preferably at least 0.91, more preferably at least 0.95. A high ratio of component (a) relative to all curable compounds present in the curable composition is preferred to obtain a membrane with high crosslink density and therefore high permselectivity. The molar fraction of component (a) relative to all curable compounds present in the curable composition is preferably at most 1.0.

[0043] The molar fraction of component (a) relative to all curable compounds present in the curable composition can be calculated by dividing the molar amount of component (a) by the sum of the molar amounts of all curable compounds present in the curable composition. Alternatively, the molar fraction can be determined by measuring the extractables from an anion exchange membrane, as described, for example, on page 19 of WO 2022 / 162083.

[0044] Preferably, the anion exchange membrane according to the present invention has an ion exchange capacity (IEC) of at least 1.1 meq / g dry membrane, more preferably at least 1.2 meq / g dry membrane, as measured by the method described below. Such an IEC can provide an anion exchange membrane with low electrical resistance.

[0045] Preferably, the anion exchange membrane according to the present invention has an IEC of less than 1.65 meq / g dry membrane as measured by the method described below. Such an IEC can provide an anion exchange membrane that does not swell excessively and therefore retains excellent permselectivity during use.

[0046] The anion exchange membrane of the present invention preferably further comprises a porous support. Examples of usable porous supports include woven and nonwoven synthetic fabrics and extruded films. Examples include wet-laid and dry-laid nonwoven materials, spunbond and meltblown fabrics, and nanofiber webs made from, for example, polyethylene, polypropylene, polyacrylonitrile, polyvinyl chloride, polyphenylene sulfide, polyester, polyamide, polyaryletherketone, such as polyetheretherketone, and copolymers thereof. The porous support can also be a porous membrane, such as polysulfone, polyethersulfone, polyphenylene sulfone, polyphenylene sulfide, polyimide, polyetherimide, polyamide, polyamideimide, polyacrylonitrile, polycarbonate, polyacrylate, cellulose acetate, polypropylene, poly(4-methyl-1-pentene), polyvinylidene fluoride, polytetrafluoroethylene, polyhexafluoropropylene, and polychlorotrifluoroethylene, and their derivatives.

[0047] The porous support preferably has an average thickness of 10 to 800 μm, more preferably 15 to 300 μm, especially 20 to 150 μm, and even more especially 30 to 130 μm, for example about 60 μm, or about 100 μm.

[0048] The porous support preferably has a porosity of 30 to 95%, more preferably 60 to 75%, in which case (in the final membrane) the pores are filled with the anion exchange polymer obtained by curing the composition, i.e. the membrane preferably comprises 25 to 40 vol% porous (unfilled) support material and 75 to 60 vol% anion exchange polymer material (i.e. the composition cured according to the first aspect of the present invention). The porosity of the support can be determined before deposition by a porometer, for example a Porolux™ 1000 from IB-FT GmbH, Germany.

[0049] If present, the porous support may be treated to modify its surface energy, for example to a value greater than 45 mN / m, preferably greater than 55 mN / m. Suitable treatments include corona discharge treatment, plasma glow discharge treatment, flame treatment, ultraviolet light irradiation treatment, chemical treatment, etc., for the purposes of improving the wettability of the porous support and the adhesion of the porous support to the anion exchange membrane.

[0050] Commercially available porous supports are available from a variety of 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.

[0051] Preferably, the porous support is a porous polymeric support. Preferably, the porous support is a woven or nonwoven synthetic fabric or an extruded film that does not have covalently attached ionic groups.

[0052] The anion exchange membrane of the present invention preferably has an average thickness of 15 μm to 600 μm, more preferably 50 μm to 450 μm, and particularly preferably 60 to 240 μm. According to a second aspect of the present invention, there is provided a process for preparing an anion exchange membrane, the process comprising curing a curable composition as defined (and preferably as defined) in relation to the first aspect of the present invention.

[0053] The process according to the second aspect of the present invention preferably comprises: i. providing a porous support; ii. impregnating a porous support with a curable composition; and iii. Curing the curable composition and the curable composition is as defined above.

[0054] The curable composition can be cured by any suitable process, examples of which include thermal curing, photocuring, electron beam (EB) irradiation, gamma irradiation, and combinations of the foregoing.

[0055] Preferably, the process according to the second aspect of the present invention comprises a first curing step and a second curing step (dual curing). Dual curing is preferred because it increases the crosslink density of the resulting anion exchange membrane, which in turn improves the permselectivity.

[0056] In a preferred embodiment of the process according to the second aspect of the present invention, the curable composition is first cured by photocuring, for example by irradiating the curable composition with ultraviolet (UV) or visible light, or by gamma or electron beam radiation, thereby polymerizing the curable components present in the curable composition, and then by applying a second curing step. The second curing step preferably involves thermal curing, gamma irradiation, or EB irradiation of the product of the first curing step, and therefore preferably applies a different curing technique than the first curing step. If gamma or electron beam irradiation is used in the first curing step, a dose of 60 to 200 kGy, more preferably 80 to 150 kGy, is applied to the curable composition.

[0057] In one embodiment, the process according to the second aspect of the present invention comprises curing a curable composition to form an anion exchange membrane in a first curing step, winding the anion exchange membrane onto a core (optionally with an inert polymer foil), and then carrying out a second curing step on the wound product of the first curing step.

[0058] In a preferred embodiment, the first and second curing steps are each selected from: (i) UV curing (first curing step) followed by thermal curing (second curing step); (ii) UV curing followed by electron beam curing; and (iii) electron beam curing followed by thermal curing.

[0059] Component (c) may contain only one radical initiator or more than one radical initiator, for example a mixture of several photoinitiators (e.g., for a single cure) or a mixture of a photoinitiator and a thermal initiator (e.g., for a dual cure).

[0060] In one embodiment, the second curing step is carried out using gamma or electron beam (EB) irradiation. For the second curing step by gamma or EB irradiation, preferably a dose of 60 to 200 kGy is applied to the product of the first curing step, more preferably a dose of 80 to 150 kGy is applied.

[0061] For the optional second curing step, heat curing is preferred. Heat curing is preferably carried out at a temperature of 50-100°C, more preferably 60-90°C. Heat curing is preferably carried out for 2-72 hours, e.g., about 3 hours for sheets, and 8-16 hours, e.g., about 10 hours for small rolls, and 24-72 hours for large rolls. After the first curing step, a polymer foil is optionally applied to the product of the first curing step before winding it onto a spool (this reduces oxygen inhibition, drying, and / or sticking of the product of the first curing step to itself).

[0062] In a preferred process according to the second aspect of the present invention, the curable composition is continuously applied to a moving (preferably porous) substrate, preferably by a manufacturing unit comprising a curable composition application station, one or more irradiation sources for curing the curable composition, a film collection station, and means for moving the substrate from the curable composition application station to the irradiation sources and further to the film collection station.

[0063] The curable composition application station may be located at an upstream position relative to the irradiation source, which is located at an upstream position relative to the film collection station. Examples of coating techniques suitable for applying the curable composition to a substrate include slot die coating, slide coating, air knife coating, roller coating, screen printing, and immersion. Depending on the technique used and the desired final specifications, it may be desirable to remove excess coating from the substrate, for example, by roll-to-roll squeeze, roll-to-blade or blade-to-roll squeeze, blade-to-blade squeeze, or removal using a coating bar. Photocuring is preferably performed for the first curing step, preferably at 40 to 20,000 mJ / cm. 2 The irradiation is typically done at a wavelength of 300 nm to 800 nm, using a dose of 1000 ppm. In some cases, additional drying may be required, in which case temperatures of 40° C. to 200° C. may be employed. If gamma or EB curing is used, irradiation may be done under low-oxygen conditions, e.g., less than 200 ppm oxygen.

[0064] According to a third aspect of the present invention there is provided the use (method of use) of an anion exchange membrane according to the first aspect of the present invention for use in an electromembrane process, for example for the treatment of polar liquids (e.g. desalination), the production of acids and bases, or the generation or storage of electricity.

[0065] According to a fourth aspect of the present invention there is provided an electrodialysis or electrodialysis reversal device, a bipolar electrodialysis device, an electrodeionization module, a flow-through capacitor, a diffusion dialysis apparatus, a membrane distillation module, an electrolyzer, a redox flow battery, an acid-base flow battery or a fuel cell comprising one or more anion exchange membranes according to the first aspect of the present invention. [Example]

[0066] The invention will now be illustrated by the following non-limiting examples in which all parts and percentages are by weight unless otherwise specified.

[0067] pH stability The pH stability of anion exchange membranes was tested by soaking a sample of the membrane under test in 4 M HCl at 80° C. for at least one month. After this treatment, the permselectivity (PS) of the membrane was measured and compared to its PS before soaking. The pH stability of a membrane was considered "OK" if the PS after soaking was at least 80% of the original PS; if it was less than 80% of the original PS, the pH stability was considered poor ("NG").

[0068] Permselectivity (PS) The permselectivity (PS) (%) (i.e., the selectivity of an anion exchange membrane for the passage of ions of opposite charge) was measured as follows: The anion exchange membrane to be tested was placed in a two-compartment system: one compartment was filled with a 0.05 M solution of HCl and the other compartment was filled with a 4 M solution of HCl, the two compartments being separated by the membrane under test.

[0069] setting: The capillary, as well as the Ag / AgCl reference electrode (Metrohm type 6.0750.100), contained 3 M KCl; Effective membrane area is 9.62cm 2 was; · The distance between the capillaries was approximately 15 mm; · The measured temperature was 21.0±0.2℃; Cole Parmer Masterflex console drives (77521-47) with easy load II model 77200-62 gear pumps were used in two compartments; The flow rate was controlled at a constant 500 ml / min using a Porter Instrument flow meter (type 150AV-B250-4RVS) and a Cole-Parmer flow meter (type G-30217-90); Prior to the measurement, the anion exchange membrane samples were equilibrated in 0.25 M HCl solution for 1 hour. After 20 minutes, the voltage was read from a standard VOM (multimeter).

[0070] The PS was calculated from the voltage readings using the Nernst equation, and preferably the PS for HCl was at least 50%.

[0071] Ion Exchange Capacity (IEC) Prior to measurement, the membranes were converted to the chloride form by soaking the samples in 2 M NaCl solution for 1 hour. The 2 M NaCl solution was replaced once, and the samples were allowed to equilibrate for an additional 24 hours. The membrane samples were then rinsed with Milli-Q water, soaked in fresh Milli-Q water for 1 hour, and rinsed again with Milli-Q water.

[0072] A 2.0 cm diameter sample was punched out from the membrane sample with chloride counterion (12.57 cm 2 ), dried at 40°C for 24 hours, and weighed. The samples were then placed in 75 ml of Milli-Q® water for 24 hours to remove all non-counterions, followed by rinsing with Milli-Q® water. Each sample was then immersed in 10.00 ml of 0.1 M AgNO3 solution, and the solution was shaken with the sample for 24 hours. During shaking, AgCl salt precipitated, resulting in AgNO3. + The ion is Cl - As ions are removed, Cl - Ions are NO3 -The AgNO3 solution was completely exchanged with the ions. The samples were then removed from the AgNO3 solution and rinsed with a small amount of Milli-Q® water. The rinse water for each sample and the corresponding AgNO3 solution remaining after shaking the membrane sample were combined and titrated with a calibrated 0.1 M KBr solution, and the results were compared to the titration value of 10.00 ml of a blank solution of 0.1 M AgNO3 containing no membrane sample. The difference in titration results between the blank solution and each sample's test solution was correlated to the ion exchange capacity of the corresponding membrane using equation (I): IEC(meq / g dry film)=(YX)×0.1 / W Equation (I) where Y is the amount (in ml) of 0.1 M KBr used in titrating the blank AgNO solution; X is the amount (in ml) of 0.1 M KBr used in titrating the AgNO solution in which the membrane sample had been immersed, combined with the Milli-Q water used to rinse the membrane sample after immersion in the AgNO solution; and W is the dry weight of the membrane (in grams).

[0073] Electrical Resistivity (ER) ER (ohm cm) of the anion exchange membranes prepared in the examples 2 ) was measured by the method described by Dlugolecki et al., J. of Membrane Science 319 (2008) pp. 217-218, with the following modifications: The auxiliary membranes were CMX and AMX from Tokuyama Soda Corporation, Japan; · The capillary, as well as the Ag / AgCl reference electrode (Metrohm type 6.0750.100) contained 3 M KCl; · The calibration liquid and the liquid in compartments 2, 3, 4 and 5 were 2.0 M NaCl solutions at 25°C; Effective membrane area is 9.62cm 2 was; · The distance between the capillaries was 5.0 mm; The measurement temperature was 25°C; · Cole-Parmer Masterflex console drives (77521-47) with Easyload II model 77200-62 gear pumps were used in all compartments; · The flow rate of each stream was 475 ml / min and was controlled by a Porter Instrument flow meter (type 150AV-B250-4RVS) and a Cole-Parmer flow meter (type G-30217-90); Prior to the measurements, the anion exchange membrane samples were equilibrated in a 0.5 M solution of NaCl at room temperature for at least 1 h.

[0074] The ER is preferably low, e.g., 15 ohm cm 2 is less than.

[0075] [Table 1]

[0076] CL-1 was synthesized as described in US20160177006, Example 1:

[0077] [ka]

[0078] General procedure for preparing AXL-1-4

[0079] [ka]

[0080] To a 40% solution (1 mmol) of the corresponding amine in PW containing 4-OH-TEMPO (0.1 g) was added dropwise CMS-14 (2.02 mmol) over 1 h. The mixture was then vigorously stirred for 2 h. Diethyl ether was added and the aqueous phase was extracted three times (3 x 200 mL). The product was isolated as a pale yellow solid from water by spray drying.

[0081] [Table 2]

[0082] Examples 1 to 6 and Comparative Examples 1 and 2.

[0083] [Table 3]

[0084] [Table 4]

[0085] The mole fraction of component (a) in Comparative Example 1 is low, resulting in a low PS. In Comparative Example 2, component (a) does not comply with formula (I).

[0086] Preparation of curable compositions and anion exchange membranes The curable compositions shown in Table 3 above were prepared by sequentially mixing the stated amounts of components (in wt%) in the stated amounts of water / n-propanol mixture at a temperature of 40°C.

[0087] Anion exchange membranes according to the first aspect of the present invention and comparative examples were prepared by applying each of the curable compositions listed in Table 3 to a porous support (PS1) at room temperature (21°C) using a 100 μm Meyer bar, removing excess curable composition using a 4 μm Meyer bar, and then curing the composition. UV curing was performed by placing a sample of the porous support containing the curable composition on a conveyor equipped with a D bulb in a Fusion UV Systems Inc. Light Hammer® 10 at 5 m / min, and exposing the curable composition to UV light emitted from the D bulb at 50% output. The UV-cured sample was covered with 60 μm polyethylene terephthalate (PET) foil (from Toray Industries, Inc.) without any surface treatment and placed in a metalized, vacuum-sealed bag. The bag containing the UV-cured membrane was then heat-cured in a conventional oven at 90°C for 3 hours (as a second curing step).

Claims

1. An anion exchange membrane obtainable by curing a curable composition, the curable composition comprising: (a) a monomer of formula (I) AR １ -(CH ２ ) ｎ -N ＋ (R ａ R ｂ )-(CH ２ ) ｎ -AR ２ 、X － Formula (I) Including, During the ceremony, each n independently has a value of 1 or 2; (i) R ａ and R ｂ each independently represents an optionally substituted C １～３ alkyl group or optionally substituted C ２～３ is an alkenyl group; or (ii) R ａ and R ｂ together with the positively charged nitrogen atom to which they are attached form an optionally substituted 5- or 6-membered ring; or (iii) R ａ and R ｂ one of which is optionally substituted C １～３ alkyl group or optionally substituted C ２～３ is an alkenyl group, and R ａ and R ｂ The other is of the formula AR １ - (CH ２ ) ｎ -N ＋ together with the group (iv) R ａ is the formula AR １ - (CH ２ ) ｎ -N ＋ together with the group R ｂ is the formula N ＋ - (CH ２ ) ｎ -AR ２ together with the group form an optionally substituted 5- or 6-membered ring; X － is an anion; AR １ and A.R. ２ each independently comprises an aromatic group; (I) AR １ and A.R. ２ at least one of which contains a curable ethylenically unsaturated group; (II) Monomer (a) of formula (I) contains at least two curable ethylenically unsaturated groups; (III) The above anion exchange membrane, wherein the molar fraction of component (a) relative to all curable components of the curable composition is at least 0.

90.

2. 2. The anion exchange membrane of claim 1, wherein n in formula (I) has a value of 1.

3. AR １ and A.R. ２ The anion exchange membrane according to claim 1 or 2, wherein each of

4. AR of formula (I) １ and A.R. ２ The anion exchange membrane according to any one of claims 1 to 3, wherein both of the groups contain a styrenyl group.

5. The anion exchange membrane according to any one of claims 1 to 4, wherein the curable composition further comprises, as monomer (b), a group having a cationic charge and one or only one curable ethylenically unsaturated group.

6. The anion exchange membrane according to any one of claims 1 to 5, wherein the curable ethylenically unsaturated group is a vinyl group.

7. 7. The anion exchange membrane according to claim 1, having an ion exchange capacity lower than 1.65 meq / g dry membrane.

8. The anion exchange membrane according to any one of claims 1 to 7, wherein the curable composition further comprises (c) a radical initiator.

9. The anion exchange membrane according to any one of claims 1 to 8, wherein the curable composition further comprises (d) a monomer that does not contain a group having a cationic charge.

10. The anion exchange membrane according to any one of claims 1 to 9, wherein the curable composition further comprises (e) a solvent.

11. The anion exchange membrane according to any one of claims 1 to 10, wherein the curable composition comprises 50 to 90 wt% of component (a), 0 to 10 wt% of component (b), 0 to 10 wt% of component (c) (radical initiator), 0 to 5 wt% of component (d) (monomer not containing a group having a cationic charge), and 10 to 40 wt% of component (e) (solvent).

12. The anion exchange membrane according to any one of claims 1 to 11, further comprising a porous support.

13. A process for preparing an anion exchange membrane, comprising curing the curable composition according to any one of claims 1 to 11.

14. (i) providing a curable composition according to claim 1; (ii) applying the curable composition onto a porous support to impregnate at least a portion of the curable composition into the porous support; and (iii) curing the curable composition 14. The process of claim 13, comprising:

15. 13. An electrodialysis device, a bipolar electrodialysis device, an electrolyzer, a redox flow battery, an acid-base flow battery or a fuel cell comprising one or more anion exchange membranes according to any one of claims 1 to 12.

16. Use of an anion exchange membrane according to any one of claims 1 to 12 for the treatment of polar liquids, for the production of acids and bases, or for the generation or storage of electricity.

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