JP2015168689A - ion exchange membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ion exchange membrane having reduced swelling caused by water containing, having excellent dimensional stability and also excellent in electrodialysis performance.SOLUTION: Provided is an ion exchange membrane comprising: a polymer (P) including a vinyl alcohol-based polymer component (A) and a vinylene-based polymer component (B); and a polymer (Q) of monomers M having ionic groups, in which, by the incorporation of the vinylene-based polymer component into the polyvinyl alcohol, the production of the ion exchange membrane having reduced swelling caused by water containing and having excellent dimensional stability is made possible.

Description

  The present invention relates to a polymer (P) containing a vinyl alcohol polymer component (A) and a vinylene polymer component (B), and an ion containing a polymer (Q) of a monomer M having an ionic group. It relates to an exchange membrane.

  Ion exchange membranes are currently used for a wide variety of applications such as seawater concentration, desalination of groundwater for drinking water and removal of nitrate nitrogen, salt removal in food manufacturing processes, and concentration of active pharmaceutical ingredients. It is used as a membrane in electrodialysis and diffusion dialysis. The main ion exchange membranes used for these are styrene-divinylbenzene-based ion exchange membranes and fluorocarbon-based ion exchange membranes.

  For styrene-divinylbenzene ion exchange membranes, anionic groups such as sulfonic acid groups and cationic groups such as quaternary ammonium groups are introduced into the styrene-divinylbenzene copolymer by post-modification. (Patent Documents 1 and 2). However, since the ion exchange membrane of a styrene-divinylbenzene polymer has poor processability of the polymer, it is necessary to impart a form using a support during polymerization, and the production cost by post-modification treatment is low. There is a problem of increase.

  In addition, perfluoroalkylsulfonic acid type polymers in which a sulfonic acid group is bonded to a side chain of a perfluoro skeleton are used for a fluorocarbon ion exchange membrane (Patent Document 3). However, the fluorocarbon-based ion exchange membrane has a problem in that it uses a fluorocarbon-based material that is difficult to significantly reduce costs because the polymer manufacturing process is complicated.

  Therefore, recently, a polyvinyl alcohol ion exchange membrane having excellent ion exchange ability and selective permeation ability, excellent organic contamination resistance, high workability, and cost reduction has been reported and attracted attention (Patent Document 4). And 5). However, since the ion exchange membrane using the polyvinyl alcohol-based copolymer uses hydrophilic polyvinyl alcohol as a base material, it is usually a bifunctional hydroxyl crosslinking agent such as glutaraldehyde or a hydroxyl group such as formaldehyde. Insolubilization with a modifier is indispensable, and even after insolubilization, the water content is high and dimensional stability may be poor, and further improvements are required.

JP 2008-266443 A JP 2008-285665 A JP 2005-78895 A Japanese Patent No. 4767683 WO2010 / 110333

  The present inventors set as a problem to be solved to provide a vinyl alcohol ion exchange membrane having practical dimensional stability and electrodialysis performance.

  As a result of intensive studies on the above problems, the present inventors have made a vinylene polymer component a component of vinyl alcohol by a simple method of highly heat-treating a mixture of a vinyl alcohol polymer and a polymer containing an ionic group. As a result of the introduction, it has been found that an ion exchange membrane with little swelling due to water content and excellent dimensional stability can be produced, and the present invention has been achieved.

The first configuration of the present invention is as follows.
It is an ion exchange membrane containing a polymer (P) containing a vinyl alcohol polymer component (A) and a vinylene polymer component (B), and a polymer (Q) of a monomer M having an ionic group. .

The polymer (P) may be a polymer represented by the following general formula (1).

[In the formula, 0.5000 ≦ (o ¹ + p ¹ ) / (n ¹ + o ¹ + p ¹ ) ≦ 0.9999, 0.750 ≦ p ¹ / (n ¹ + o ¹ + p ¹ ) ≦ 0.999 is there. ]

The ionic group may be an anionic group or a cationic group.

  A crosslink may be introduced into the ion exchange membrane.

  The ion exchange membrane may contain a reinforcing material.

  The reinforcing material may be a continuous support made of a porous film, a mesh, or a nonwoven fabric.

The nonwoven fabric may be a wet nonwoven fabric of polyvinyl alcohol-based short fibers.

  In the second configuration of the present invention, a film-form molded product containing a vinyl alcohol polymer and a polymer (Q) of a monomer M having an ionic group as components is heat-treated under acidic conditions to form a dehydrated polyene. A method for producing an ion exchange membrane, comprising introducing a vinyl alcohol polymer component (A) and a polymer (P) containing a vinylene polymer component (B) by It is.

  In the ion exchange membrane of the present invention, by introducing a vinylene polymer component, a low water content is achieved and water resistance is imparted. For this reason, it is possible to provide an ion exchange membrane that is less swelled by water and has excellent dimensional stability.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims.
It is explanatory drawing sectional drawing of the apparatus used for the measurement of the dynamic transport number of the ion exchange membrane of this invention. It is explanatory drawing sectional drawing of the apparatus used for the measurement of the membrane resistance of the ion exchange membrane of this invention.

  Hereinafter, the present invention will be described in detail. The ion exchange membrane according to the present invention comprises a polymer (P) containing a vinyl alcohol polymer component (A) and a vinylene polymer component (B), and a polymer of a monomer M having an ionic group (Q ).

  A preferable structure of the polymer (P) includes a polymer represented by the general formula (1).

In the general formula (1), (o ¹ + p ¹ ) / (n ¹ + o ¹ + p ¹ ) is other than vinyl acetate units contained in the vinyl alcohol polymer component (A) and the vinylene polymer component (B). The ratio is shown. About a minimum, it is 0.5000 or more, More preferably, it is 0.7000 or more, More preferably, it is 0.8000 or more. On the other hand, the upper limit is preferably 0.9999 or less, more preferably 0.999 or less, and still more preferably 0.995 or less.

In the general formula (1), p ¹ / (n ¹ + o ¹ + p ¹ ) is a ratio of the vinylene polymer component (B) contained in the vinyl alcohol polymer component (A) and the vinylene polymer component (B). This is the polyene conversion rate. The lower limit of the polyene conversion rate is 0.750 or more, more preferably 0.800 or more, and further preferably 0.850 or more. On the other hand, the upper limit is preferably 0.999 or less, more preferably 0.99 or less, and still more preferably 0.95 or less.

In the general formula (1), the monomer repeating units n ¹ , o ¹ , and p ¹ do not mean that they are arranged as shown, but simply indicate that each unit exists. Usually, they are arranged randomly at the same time, but the same unit may be continuous.

  Examples of the monomer M having an ionic group of the polymer (Q) include units composed of at least one ionic group and at least one ethylenically unsaturated monomer.

  Examples of the ionic group include an anionic group and a cationic group.

Examples of the anionic group include a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boronic acid group, and a sulfonylimide group. Although it does not specifically limit as a cation of a counter, Monovalent cations, such as an alkali metal ion, H ^<+> , quaternary ammonium ion, are preferable.

Examples of cationic groups include amino groups such as unsubstituted amino groups, N-alkylamino groups, and N-dialkylamino groups, nitrogen-containing heterocycles such as pyridyl groups and imidazolyl groups, N-trialkylammonium groups, and N-alkyls. Examples thereof include quaternary ammonium groups such as a pyridinium group, an N-alkylimidazolium group, a thiouronium group, and an isothiouronium group. The anion of the quaternary ammonium group counter is not particularly limited, but a halogenated anion of a group 5B element such as PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ^−, a halogenated anion of a group 3B element such as BF ₄ ⁻ , I ^{_{- (I 3 -), Br}} -, Cl - and a halogen anion, ClO ₄ ^- halogen anion such ^{_{as, AlCl 4 -, FeCl 4 -}} , SnCl 5 - represented by ^- metal halide anions such as, NO ₃ Nitrate anion, p-toluenesulfonate anion, naphthalenesulfonate anion, organic sulfonate anions such as CH ₃ SO ₃ ⁻ and CF ₃ SO ₃ ^— , carboxylate anions such as CF ₃ COO ⁻ and C ₆ H ₅ COO ⁻ , OH ^- 1 monovalent anion, and the like are preferable.

  Examples of the ethylenically unsaturated monomer include α-olefins such as ethylene, propylene, n-butene, and isobutylene; styrenes such as styrene and α-methylstyrene; acrylic acid, methyl acrylate, ethyl acrylate, acrylic Acrylic acid or esters thereof such as n-propyl acid, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid Methacrylic acid or esters thereof such as n-propyl, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate; acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetone Acrylamides such as chloramide; Methacrylamides such as methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, methacrylamidepropyldimethylamine; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n- Vinyl ethers such as butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, 2,3-diacetoxy-1-vinyloxypropane; allyl acetate, 2,3-diacetoxy-1-allyloxypropane, Examples include allyl compounds such as allyl chloride; unsaturated dicarboxylic acids such as maleic acid, itaconic acid, fumaric acid, and esters thereof.

Examples of the monomer M having an ionic group include the following general formulas (2) to (18).

[Wherein, R ¹ represents a hydrogen atom or an alkali metal atom. ]

[Wherein, R ¹ has the same meaning as described above. ]

[Wherein, R ¹ has the same meaning as described above. ]

[Wherein, R ¹ has the same meaning as described above. ]

[Wherein, R ¹ has the same meaning as described above. ]

[Wherein, R ¹ is as defined above, and R ² is a hydrogen atom or a methyl group. ]

[Wherein, R ¹ and R ² are as defined above. ]

[Wherein, X ⁻ represents a halogenated anion of a group 5B element such as PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ^−, a halogenated anion of a group 3B element such as BF ₄ ⁻ , I ⁻ (I ₃ ⁻ ), Halogen anions such as Br ⁻ and Cl ⁻ , halogen acid anions such as ClO ₄ ⁻ , metal halide anions such as AlCl ₄ ⁻ , FeCl ₄ ⁻ and SnCl ₅ ⁻ , nitrate anions represented by NO ₃ ⁻ , p-toluenesulfone Monovalent cation such as acid anion, naphthalene sulfonate anion, organic sulfonate anion such as CH ₃ SO ₃ ⁻ and CF ₃ SO ₃ ^— , carboxylic acid anion such as CF ₃ COO ⁻ and C ₆ H ₅ COO ⁻ , and OH ⁻ An anion, and R ² is as defined above. ]

[Wherein, X ⁻ has the same meaning as described above. ]

[Wherein, X ⁻ has the same meaning as described above. ]

[Wherein, X ⁻ has the same meaning as described above. ]

[Wherein, X ⁻ has the same meaning as described above. ]

[Wherein, R ² has the same meaning as described above and may be the same as or different from each other. ]

[Wherein, R ² has the same meaning as described above. ]

  The polymer (Q) may be composed of a single monomer M, or may be composed of two or more monomers M.

  The method for producing the polymer (Q) from the monomer M is not particularly limited, but it is preferable to use a known polymerization method such as radical polymerization, cationic polymerization, anionic polymerization, coupling polymerization, etc. Radical polymerization in an aqueous solution using an agent is more preferable.

  Although it does not specifically limit as a weight average polymerization degree of a polymer (Q), Preferably it is 100-10,000, More preferably, it is 100-7,000, More preferably, it is 500-5,000. When the weight average degree of polymerization is less than 100, the durability of the ion exchange membrane may be lowered.

  Ion containing the polymer (P) containing the vinyl alcohol polymer component (A) and the vinylene polymer component (B) according to the present invention, and the polymer (Q) of the monomer M having an ionic group A method for producing an exchange membrane is generally performed by preparing an intermediate (precursor) containing a vinyl alcohol polymer and a polymer (Q) of a monomer M having an ionic group, It consists of a step II for producing a film-like formed body by imparting a desired form and a step III for producing an ion exchange membrane according to the present invention by dehydration polyeneation reaction.

  Step I includes (Ia) a method of producing an intermediate by mixing a vinyl alcohol polymer and a polymer (Q) of a monomer M having an ionic group, or (Ib) a vinyl alcohol polymer and an ionic property. The polymerization initiator is added to the solution containing the monomer M having a group to produce an intermediate. Since the type and amount of each component can be easily controlled, the production method (Ia) is preferable.

  The viscosity average degree of polymerization measured according to JIS K6726 of the vinyl alcohol polymer used in the present invention is not particularly limited, preferably 100 to 10,000, more preferably 300 to 7,000, Preferably it is 500-5,000. When the viscosity average degree of polymerization is less than 100, the mechanical strength when an ion exchange membrane is obtained may be lowered. A polyvinyl alcohol polymer having a viscosity average polymerization degree exceeding 10,000 is difficult to produce industrially.

  The saponification degree of the vinyl alcohol polymer used in the present invention is 50 mol% or more, more preferably 80 to 99.99 mol%, particularly preferably 90 to 99.5 mol%.

Since the vinyl alcohol polymer is converted into a polymer (P) containing the vinyl alcohol polymer component (A) and the vinylene polymer component (B) as a constituent component by the dehydration polyene conversion reaction, it is used as a raw material. The saponification degree of the vinyl alcohol polymer was equal to (o ¹ + p ¹ ) / (n ¹ + o ¹ + p ¹ ) in the general formula (1).

  The mixing ratio of the vinyl alcohol polymer and the polymer (Q) of the monomer M having an ionic group is not particularly limited, but the weight of the vinyl alcohol polymer Wa is the monomer M having an ionic group. When the weight (Wq) of the polymer (Q) is given as [Wq / (Wa + Wq)] indicating the weight ratio of the polymer (Q) of the monomer M having an ionic group, 0.05 <[Wq / ( Wa + Wq)] <1.0, more preferably 0.10 <[Wq / (Wa + Wq)] <0.75, and even more preferably 0.15 <[Wq / (Wa + Wq)] < 0.50.

  The form of the intermediate containing the vinyl alcohol polymer and the polymer (Q) of the monomer M having an ionic group is not particularly limited, but it should be a solution in consideration of processability in Step II. Preferably, the solvent is not particularly limited, but water, methanol, ethanol, isopropanol, diethyl ether, tetrahydrofuran, 1,4-dioxane, acetone, methyl ethyl ketone, N-methylpyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, Examples thereof include polar solvents such as methyl ethyl sulfoxide and diethyl sulfoxide, or mixed solvents thereof, and water is more preferable from the viewpoint of solubility. Although the density | concentration of a solution is not specifically limited, 0.1-50 mass parts is preferable with respect to 100 mass parts of said solvent, More preferably, it is 5-30 mass parts.

  The intermediate containing the vinyl alcohol polymer and the polymer (Q) of the monomer M having an ionic group may contain any additive as required, and the order of addition is also Can be arbitrarily selected. The additive can be appropriately selected from known additives, for example, metal fine particles, inorganic fine particles, inorganic salts, ultraviolet absorbers, antioxidants, deterioration inhibitors, dispersants, surfactants, Examples thereof include polymerization inhibitors, thickeners, conductive assistants, surface modifiers, antiseptics, antifungal agents, antibacterial agents, antifoaming agents, and plasticizers. These may be used alone or in combination of two or more.

  The intermediate solution containing the vinyl alcohol polymer and the polymer (Q) of the monomer M having an ionic group has a pH of 3.0 to facilitate the introduction of the vinylene polymer component in Step III. Preferably, the pH is less than 2.0, more preferably acidic compounds such as sulfuric acid, hydrochloric acid, acetic acid and ammonium chloride, and basic compounds such as sodium hydroxide, potassium hydroxide, ammonia and sodium acetate. May be added as appropriate, pH may be adjusted, pH may be adjusted using ion exchange resins such as anion exchange resin and cation exchange resin, pH may be adjusted by electrodialysis, The method for adjusting pH is not particularly limited.

  Step II is a step of producing a film-shaped formed body from the intermediate obtained in Step I.

  Although it does not specifically limit as a manufacturing method of a film-shaped molded object, For example, after casting a solution into a film shape, for example, a melt-molding method (for example, extrusion molding method, injection molding method, inflation molding method, press molding method, blow molding method) For example, a solvent casting method for forming a film by removing the solvent by drying may be used.

  When using the melt molding method, an arbitrary thermoplastic resin may be added as necessary, and the order of the addition may be arbitrarily selected. The thermoplastic resin is not particularly limited, and a general thermoplastic resin can be used.

  When using the solvent casting method, it can be performed using a casting machine, a film applicator, etc., but is not particularly limited thereto, on a polymer film such as polyethylene terephthalate film, nylon film, polypropylene, or copper foil They may be laminated on a metal foil such as an aluminum foil, or on an inorganic substrate such as a glass substrate or a silicon substrate, or may have a multilayer structure.

In Step II, in addition to the above-described production method, reinforcement by adding a reinforcing material made of an inorganic material, an organic material, or an organic-inorganic hybrid material can be performed. The reinforcing material may be a fibrous material, a particulate material, or a flaky material. Further, a continuous support such as a porous film, a mesh, and a nonwoven fabric may be used. In the present embodiment, the mechanical strength and dimensional stability can be improved by performing the reinforcement by the addition of the reinforcing material. In particular, when a fibrous material or the above-described continuous support is used as a reinforcing material, the reinforcing effect is high. Moreover, what laminated | stacked the layer which does not reinforce and the layer which carried out the said reinforcement layer in the multilayer form by arbitrary methods is also preferable.
The reinforcing material may be added and mixed at the time of processing into a film-shaped molded body, may be impregnated with a solution containing an intermediate, or may be laminated with a film after film formation.

  The nonwoven fabric is preferably a wet nonwoven fabric formed from short fibers. Wet non-woven fabric is made by dispersing main fibers and a small amount of binder fibers that bond between the main fibers in water and making them uniform slurry under gentle agitation. A sheet can be formed and manufactured using a papermaking apparatus having at least one of the wires.

  For example, the polymer forming the nonwoven fabric (or the constituent polymer of the main fiber) is not particularly limited, and examples thereof include polyester (PET, PTT, etc.), polyvinyl alcohol, and the like, and polyvinyl alcohol is particularly preferable. A particularly preferable nonwoven fabric sheet includes a wet nonwoven fabric mainly composed of polyvinyl alcohol short fibers.

The inorganic material used as the reinforcing material is not particularly limited as long as it has a reinforcing effect. For example, glass fiber, carbon fiber, cellulose fiber, kaolin clay, kaolinite, halloysite, pyrophyllite, talc, montmorillonite, sericite, mica Amesite, bentonite, asbestos, zeolite, calcium carbonate, calcium silicate, diatomaceous earth, silica sand, iron ferrite, aluminum hydroxide, aluminum oxide, magnesium oxide, titanium oxide, zirconium oxide, graphite, fullerene, carbon nanotube, And carbon nanohorn. The organic material used as the reinforcing material is not particularly limited as long as it has a reinforcing effect. For example, polyvinyl alcohol, polyphenylene sulfide, polyphenylene ether, polysulfone, polyether sulfone, polyether ether sulfone, polyether ketone, polyether ether ketone. , Polythioether sulfone, polythioether ether sulfone, polythioether ketone, polythioether ether ketone, polybenzimidazole, polybenzoxazole, polyoxadiazole, polybenzoxazinone, polyxylylene, polyphenylene, polythiophene, polypyrrole, polyaniline, polyacene, polycyanogen , Polynaphthyridine, polyphenylene sulfide sulfone, polyphenylene sulfone, polyimide, Reetherimide, polyesterimide, polyamideimide, polyamide, aromatic polyamide, polystyrene, acrylonitrile-styrene resin, polystyrene-hydrogenated polybutadiene-polystyrene block copolymer, acrylonitrile-butadiene-styrene resin, polyester, polyarylate, liquid crystal Polyester, polycarbonate, polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyvinylidene chloride, vinylon fiber, methacrylic resin, epoxy resin, phenol resin, melamine resin, urethane resin, cellulose, polyketone, polyacetal, polypropylene, polyethylene, etc. Can be mentioned. An organic-inorganic hybrid material can also be used as a reinforcing material, and examples thereof include an organic silicon polymer compound having a silsesquioxane structure or a siloxane structure such as POSS (Polyhedral Oligomeric Silsesquioxanes) or silicone rubber.

In Step III, a dehydrated polyene reaction is performed on the film-like molded product containing the vinyl alcohol polymer obtained in Step II and the polymer (Q) of the monomer M having an ionic group as components. A polymer (P) containing a vinyl alcohol polymer component (A) and a vinylene polymer component (B), and an ion exchange membrane containing a polymer (Q) of a monomer M having an ionic group Is a process of manufacturing.

  Examples of the dehydration polyene reaction include heat treatment, which can be changed depending on the type and form of the film-shaped molded body, but generally known methods can be used, for example, hot air dryers, hot presses, hot plates, infrared heaters. A roller heater or the like can be used. When performing heat treatment of a large area, a planar heating means is preferable, and a hot press, a hot plate, an infrared heater, a roller heater, and the like are more preferable. The conditions for the heat treatment are not particularly limited, and the heat treatment temperature is preferably 100 to 250 ° C., more preferably 140 to 200 ° C., and the heating time is preferably in the atmosphere, an inert gas atmosphere such as nitrogen, or reduced pressure. It is 5 seconds to 4 hours, more preferably 1 minute to 2 hours, and the heat treatment may be performed in a plurality of times.

  The ion exchange membrane obtained in Step III may be subjected to a crosslinking treatment as necessary. By performing the cross-linking treatment, cross-linking is introduced, and the electrodialysis performance can be further improved. The method for the crosslinking treatment is not particularly limited as long as it is a method capable of bonding the molecular chains of the polymer by chemical bonding. Usually, a method of immersing in a solution containing a crosslinking agent is used. Examples of the crosslinking agent include formaldehyde or dialdehyde compounds such as glyoxal and glutaraldehyde.

In the present invention, when the film-shaped molded article is produced in Step II, the above crosslinking agent is mixed in advance, and the crosslinking treatment is performed simultaneously with Step III. After the heat treatment, water, alcohol under acidic conditions Or the method of performing a crosslinking process by immersing in the solution formed by dissolving a dialdehyde compound in those mixed solvents is mentioned, It is preferable to carry out by the latter method in consideration of process passability. When the crosslinking treatment is performed by the latter method, the concentration of the crosslinking agent is usually 0.001 to 10% by volume of the crosslinking agent with respect to the solution.

  Hereinafter, examples will be given to describe the present invention in more detail, but the present invention is not limited to these examples.

<Measurement of dynamic transportation>
The dynamic transport number of the ion exchange membrane is such that the ion exchange membrane is sandwiched in a two-chamber cell having a platinum black electrode plate shown in FIG. 1, and 0.5 mol / L-NaCl solution is filled on both sides of the ion exchange membrane. Went. Using ion chromatography, the change in the amount of ions before and after dialysis was calculated and substituted into the following equation to calculate the dynamic transport number t _d ^± .
t _d ^± = Δm / Ea
t _d ^± : Dynamic transport number Ea: Theoretical equivalent = I · t / F
Δm: moving equivalent F: Faraday constant

<Measurement of membrane resistance>
The membrane resistance was determined by sandwiching an ion exchange membrane in a two-chamber cell having a platinum black electrode plate shown in FIG. 2, filling a 0.5 mol / L-NaCl solution on both sides of the membrane, and an AC bridge (frequency 1000 cycles / second). Then, the resistance between the electrodes at 25 ° C. was measured, and the resistance was calculated from the difference between the resistance between the electrodes and the resistance between the electrodes when no ion exchange membrane was installed. The membrane used for the above measurement was previously equilibrated in a 0.5 mol / L-NaCl solution.

<Polyene conversion rate measurement>
Weight after film formation after drying at 80 ° C. for 30 minutes using a hot air dryer is [weight before polyeneization], and then heat treatment is performed at 160 ° C. for 30 minutes using a high temperature heat treatment machine Is [weight after polyeneization], all of the above weight reduction ([weight before polyeneization]-[weight after polyeneization]) is dehydrated by the heat treatment of the vinyl alcohol polymer component (44.05 g / mol). Therefore, the conversion rate was defined as the polyene conversion rate as a result of weight reduction due to conversion to the vinylene polymer component (26.04 g / mol). For the material containing the reinforcing material, the weight of the copolymer was obtained by subtracting the weight of the reinforcing material from the total weight of the membrane.

<Synthesis Example 1>
In a 500 mL four-necked separable flask equipped with a reflux condenser and a stirring blade, 181 g of water, polyvinyl alcohol PVA-117 (viscosity average polymerization degree 1700, saponification degree 98.5 mol%, purity 97%): Kuraray ) And 58.2 g of polystyrene sulfonic acid (weight average molecular weight 75000, 18% aqueous solution: Sigma-Aldrich) were charged, and the mixture was heated to 90 ° C. with stirring and dissolved while bubbling nitrogen to obtain aqueous solution S-1. Got. The pH of the aqueous solution was 0.9.

<Synthesis Example 2>
In a 500 mL four-necked separable flask equipped with a reflux condenser and a stirring blade, 263 g of water, polyvinyl alcohol PVA-117 (viscosity average polymerization degree 1700, saponification degree 98.5 mol%, purity 97%): Kuraray ) And 6.2 g of sodium parastyrene sulfonate (purity 90%: manufactured by Tosoh Organic Chemical) were heated to 90 ° C. with stirring and dissolved while bubbling nitrogen. After nitrogen substitution, 22.4 mL of a 2.0% aqueous solution of 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -2-propionamide] was sequentially added to the above aqueous solution over 1.5 hours. Polymerization is started by adding to the polymer, and then allowed to proceed. Then, the system temperature is maintained at 90 ° C. for 4 hours to further promote the polymerization, and then cooled, and concentrated sulfuric acid is added to adjust the pH to 1.0. An aqueous solution S-2 was obtained.

<Synthesis Example 3>
In a 500 mL four-necked separable flask equipped with a reflux condenser and a stirring blade, 269 g of water, polyvinyl alcohol PVA-117 (viscosity average polymerization degree 1700, saponification degree 98.5 mol%, purity 97%): Kuraray ) And 26.2 g of 2-acrylamido-2-methylpropanesulfonic acid (purity 97%: manufactured by Wako Pure Chemical Industries, Ltd.) were charged, and the mixture was heated to 90 ° C. with stirring and dissolved while bubbling nitrogen. After nitrogen substitution, 23.8 mL of a 2.0% aqueous solution of 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -2-propionamide] was sequentially added to the above aqueous solution over 1.5 hours. The polymerization was started and proceeded by adding to the system, and then the system temperature was maintained at 90 ° C. for 4 hours to further proceed the polymerization, followed by cooling to obtain an aqueous solution S-3. The pH of the aqueous solution was 0.9.

<Synthesis Example 4>
In a 500 mL four-necked separable flask equipped with a reflux condenser and a stirring blade, 224 g of water, polyvinyl alcohol PVA-117 (viscosity average polymerization degree 1700, saponification degree 98.5 mol%, purity 97%): Kuraray ) And 11.13 g of vinyl sulfonic acid (purity 95%: manufactured by Asahi Kasei Finechem) were heated to 90 ° C. with stirring and dissolved while bubbling nitrogen. After nitrogen substitution, 9.9 mL of a 2.0% aqueous solution of 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -2-propionamide] was sequentially added to the above aqueous solution over 1.5 hours. The polymerization was started and allowed to proceed, and then the system temperature was maintained at 90 ° C. for 4 hours to further advance the polymerization, followed by cooling to obtain an aqueous solution S-4. The pH of the aqueous solution was 0.9.

<Synthesis Example 5>
In a 500 mL four-necked separable flask equipped with a reflux condenser and a stirring blade, 268 g of water, polyvinyl alcohol PVA-117 (viscosity average polymerization degree 1700, saponification degree 98.5 mol%, purity 97%): Kuraray ) And 25.6 g of vinylbenzyltrimethylammonium chloride (purity 97%: manufactured by AGC Seimi Chemical) were heated to 90 ° C. with stirring and dissolved while bubbling nitrogen. After nitrogen substitution, 23.2 mL of a 2.0% aqueous solution of 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -2-propionamide] was sequentially added to the above aqueous solution over 1.5 hours. Polymerization is started by adding to the polymer, and then allowed to proceed. Then, the system temperature is maintained at 90 ° C. for 4 hours to further promote the polymerization, and then cooled, and concentrated sulfuric acid is added to adjust the pH to 1.0. As a result, an aqueous solution S-5 was obtained.

  <Synthesis Example 6> To a 500 mL four-necked separable flask equipped with a reflux condenser and a stirring blade, 263 g of water, polyvinyl alcohol PVA-117 (viscosity average polymerization degree 1700, saponification degree 98.5 mol%, purity 97% ( Co.): 50.0 g of Kuraray Co., Ltd.) and 6.2 g of sodium styrenesulfonate (purity 90%: manufactured by Tosoh Organic Chemical Co., Ltd.) were charged to 90 ° C. with stirring and dissolved while bubbling nitrogen. After nitrogen substitution, 22.4 mL of a 2.0% aqueous solution of 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -2-propionamide] was sequentially added to the above aqueous solution over 1.5 hours. The polymerization was started and allowed to proceed, and then the system temperature was maintained at 90 ° C. for 4 hours to further advance the polymerization, followed by cooling to obtain an aqueous solution S-6. The pH of the aqueous solution was 6.8.

<Example 1>
The aqueous solutions S-1 to S-5 obtained in Synthesis Examples 1 to 5 were applied on a PET film with a gap of 500 μm using an applicator bar, and then dried at 80 ° C. for 30 minutes with a hot air dryer. Thereafter, the PET film was peeled off, and heat treatment was performed at 160 ° C. for 30 minutes using a high-temperature heat treatment machine to obtain ion exchange membranes M-1 to M-5 containing a polyene polymer component. The polyene conversion rate, membrane resistance, and dynamic transport number of the obtained ion exchange membrane were measured. The results are shown in Table 1.

<Example 2>
After applying the aqueous solutions S-1 to S-5 obtained in Synthesis Examples 1 to 5 on a PET film using an applicator bar with a gap of 500 μm, the vinylon nonwoven fabric BNF No. 2 (manufactured by Kuraray Co., Ltd.) was bonded and dried at 80 ° C. for 30 minutes using a hot air dryer. Thereafter, the PET film was peeled off, and heat treatment was carried out at 160 ° C. for 30 minutes with a high-temperature heat treatment machine to obtain N-1 and N-5 containing a polyene polymer component. The polyene conversion rate, membrane resistance, and dynamic transport number of the obtained ion exchange membrane were measured. The results are shown in Table 1.

<Comparative Example 1>
Using the aqueous solution S-6 obtained in Synthesis Example 6, an ion exchange membrane M-6 was obtained in the same manner as in Example 1. The polyene conversion rate, membrane resistance, and dynamic transport number of the obtained ion exchange membrane were measured. The resulting ion exchange membrane was so leached into water that membrane resistance and dynamic transport number could not be measured. The results are shown in Table 1.

<Comparative Example 2>
Using the aqueous solution S-6 obtained in Synthesis Example 6, an ion exchange membrane N-6 was obtained in the same manner as in Example 2. The polyene conversion rate, membrane resistance, and dynamic transport number of the obtained ion exchange membrane were measured. The resulting ion exchange membrane was so leached into water that membrane resistance and dynamic transport number could not be measured. The results are shown in Table 1.

  It can be seen from Table 1 that water resistance is imparted without introducing a cross-linking treatment by introducing a vinylene polymer component by polyene reaction, and the performance as an ion exchange membrane is expressed (Examples 1 and 2). . On the other hand, when polyene-ized reaction was not performed, it was inferior to water resistance (Comparative Examples 1-2).

  The copolymer of the present invention includes an ion exchange resin, an ion exchange membrane, an ion adsorbing material, a solid electrolyte for a fuel cell, a conductive polymer material, an antistatic material, a primary battery, a secondary battery, a solid electrolytic capacitor, an ink, and a binder. Since it can be widely used as a base material and a modifier for various materials such as (adhesives), health care products such as pharmaceuticals and cosmetics, food additives, and detergents, it has industrial applicability.

  While the preferred embodiments of the present invention have been described above by way of example, those skilled in the art can make various modifications, additions and substitutions without departing from the spirit and spirit of the present invention disclosed in the claims. Is understandable.

A: Power source B: Ampere meter C: Coulomb meter D: Volt meter E: Motor F: Stirrer G: Cathode electrode H: Anode electrode I: 0.5M NaCl aqueous solution J: Ion exchange membrane (effective membrane area 8.0 cm2)
K: ion exchange membrane (effective area 1.0 cm2)
L: Platinum electrode M: NaCl aqueous solution N: Water bath O: LCR meter

Claims (9)

  An ion exchange membrane comprising a polymer (P) containing a vinyl alcohol polymer component (A) and a vinylene polymer component (B), and a polymer (Q) of a monomer M having an ionic group. The polymer (P) is represented by the following general formula (1)

[In the formula, 0.5000 ≦ (o ¹ + p ¹ ) / (n ¹ + o ¹ + p ¹ ) ≦ 0.9999, 0.750 ≦ p ¹ / (n ¹ + o ¹ + p ¹ ) ≦ 0.999 The ion exchange membrane according to claim 1, wherein   The ion exchange membrane according to claim 1 or 2, wherein the ionic group is an anionic group.   The ion exchange membrane according to claim 1 or 2, wherein the ionic group is a cationic group.   The ion exchange membrane according to any one of claims 1 to 4, wherein a cross-linked bond is introduced.   The ion exchange membrane according to claim 1, comprising a reinforcing material.   The ion-exchange membrane according to claim 6, wherein the reinforcing material is a continuous support made of a porous membrane, a mesh, or a nonwoven fabric.   The ion exchange membrane according to claim 7, wherein the nonwoven fabric is a wet nonwoven fabric of polyvinyl alcohol-based short fibers.   A film-like molded product containing a vinyl alcohol polymer and a polymer (Q) of a monomer M having an ionic group as components is heat-treated under acidic conditions, and dehydrated polyene is converted into a vinyl alcohol polymer component (A ) And a polymer (P) containing a vinylene polymer component (B) are introduced. The method for producing an ion exchange membrane according to claim 1, wherein the polymer (P) is introduced.

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