KR102241065B1 - An anion-exchange membrane and a method for manufacturing the same - Google Patents

Abstract

An embodiment of the present invention is _{a continuous phase matrix comprising a polyolefin having a weight average molecular weight (M w} ) of 250,000 to 450,000, and a porous support comprising a crosslinked discontinuous silane-modified polyolefin in the matrix; And an anion conductive material impregnated into the pores of the porous support or applied to the surface thereof.

Description

Anion exchange membrane and its manufacturing method {AN ANION-EXCHANGE MEMBRANE AND A METHOD FOR MANUFACTURING THE SAME}

The present invention relates to an anion exchange membrane and a method of manufacturing the same, and more specifically, an anion exchange membrane applicable to CDI (Capacitive Deionization), ED (Electrodialysis), RED (Reverse Electrodialysis), Water Electrolysis, etc. It's about the method.

Ion exchange membranes are used in various fields such as fuel cells, redox flow cells, water treatment, and seawater desalination. Ion exchange membranes are attracting worldwide attention as a major clean technology capable of reducing environmental pollution by reducing the use of fossil raw materials, especially because of their relatively simple manufacturing process, excellent selectivity for specific ions, and a wide range of applications. The ion exchange membrane as described above can selectively separate cations and anions in aqueous solutions, such as fuel cells, electrodialysis, water decomposition electrodialysis for recovering acids and bases, diffusion dialysis for recovering acids and metal species from pickling waste, ultrapure water. It is widely used, such as a process, and as high-performance ion exchange membranes have recently been developed in advanced countries, their application range is further expanding.

These ion exchange membranes must have high selectivity and require low permeability of solvents and non-ionic solutes, low resistance to diffusion of selected permeated ions, high mechanical strength and chemical resistance. These ion exchange membranes are required to have excellent mechanical strength and durability. Methods commonly used to meet this demand include a method of preparing a hybrid composite film by adding an inorganic substance, a hot press method of heat-pressing a catalyst mixture, a method of adding a curing agent, and the like.

The hybrid composite membrane has a disadvantage in that if the swelling phenomenon of the membrane continues, a gap is created between the additives of the membrane and the polymer membrane, so that normal ion exchange capability cannot be exhibited. In addition, the method of adding the curing agent also has a disadvantage that the curing agent is eluted over time. Due to the above-described problems, there is still a need to develop an ion exchange membrane having high durability and excellent mechanical properties.

Currently commercialized anion exchange membranes include Asahi Glass's Selemion ^TM AMV, Astom's Neosepta ^TM AMX, and the like.

However, in the case of a commercially available anion exchange membrane, it is vulnerable to membrane contamination by organic matter and scaling of inorganic matter. In particular, membrane contamination by organic matter occurs when membrane contaminants with low mobility pass through the anion exchange membrane. To solve this problem, there is a method of lowering the degree of crosslinking so as to increase the permeability of an organic material having a relatively large molecular weight, but in this case, there is a problem that the mechanical strength and chemical stability of the membrane are lowered.

In addition, in the case of a commercially available anion exchange membrane, while excellent ion exchange capacity and electrical properties, there is a problem that the price is expensive and durability is low.

The present invention is to solve the problems of the prior art described above, the object of the present invention is excellent in mechanical properties and ion exchange ability, it can be implemented uniformly, and the production cost increases according to the elution and disposal of alkoxyvinylsilane. To solve the problem, to provide an anion exchange membrane with excellent economical efficiency and a manufacturing method thereof.

One aspect of the present invention is _{a continuous phase matrix comprising a polyolefin having a weight average molecular weight (M w} ) of 250,000 to 450,000, and a porous support comprising a crosslinked discontinuous silane-modified polyolefin in the matrix; And an anion conductive material impregnated in the pores of the porous support or applied to the surface thereof.

In one embodiment, the content of the silane-modified polyolefin in the porous support may be 0.1 to 5% by weight.

In one embodiment, the silane may be a vinyl silane containing an alkoxy group.

In one embodiment, the anion conductive material may be an aminated polymer.

In one embodiment, the aminated polymer may have a structure represented by Formula 1 below.

<Formula 1>

In the above formula, Y is a covalent bond (-), -CO-, -SO ₂ -, or -O-, Z and D are each covalent bond (-), -O-, or -S-, and C is covalent A bond (-), -C(CH ₃ ) ₂ -, or -C(CF ₃ ) ₂ -, and R ₁ is H, or -CH ₂ N ⁺ R ₂ R ₃ R ₄ , and R ₂ , R ₃ , R ₄ is -CH ₃ , -CH ₂ CH ₃ , -(CH ₂ ) ₂ CH ₃ , -CH ₂ NH ₂ , -(CH ₂ ) ₂ NH ₂ , or -(CH ₂ ) ₃ NH(CH ₃ ) Cl, x and y are each arbitrary repeating unit, and x/(x+y) is 0.001 to 1.

In one embodiment, the aminated polymer is aminated PAES (polyaryleneether sulfone), aminated PEK (polyether keton), aminated PEEK (polyetherether ketone), aminated PS (polysulfone), aminated PES (polyether sulfone), aminated PPO (polyphenylene). oxide), aminated polyphenylene sulfide (PPS), and a combination of two or more of them.

In one embodiment, the porous support may further include an inorganic filler, and the content of the inorganic filler in the porous support may be 10 to 70% by weight.

Another aspect of the present invention is, (a) manufacturing a porous support by processing a composition comprising a polyolefin having _{a weight average molecular weight (M w) of 250,000 to 450,000 and a silane-modified polyolefin;} (b) crosslinking the silane-modified polyolefin contained in the porous support; And (c) impregnating the porous support in a solution containing an anion conductive material and a solvent.

In one embodiment, prior to step (c), plasma treatment of the porous support in the presence of bromine gas, and dimolecular nucleophilic substitution reaction (S _N 2 reaction) with a compound containing an amine group; further comprising can do.

In one embodiment, the plasma treatment may be performed for 0.5 to 90 minutes.

An anion exchange membrane according to an aspect of the present invention and a method of manufacturing the same, in the manufacture of a support of the anion exchange membrane, use a polyolefin having completed silane modification without separately performing a silane modification reaction of the polyolefin, which is a weight average molecular weight within a certain range. Eggplants can be uniformly implemented while having excellent mechanical properties by mixing them with polyolefins in a certain ratio, and can maximize productivity and economy by solving the problem of increasing the manufacturing cost according to the elution and disposal of alkoxyvinylsilane.

According to another aspect of the present invention, the support of the anion exchange membrane is plasma-treated with the porous support in the presence of bromine gas, and a dimolecular nucleophilic substitution reaction (S _N 2 reaction) with a compound containing an amine group is performed to obtain the surface and interior of the support. By hydrophilizing the surface of the pores, it is possible to improve the bonding strength with the anion conductive material impregnated in the support, and thus durability and ionic conductivity of the anion exchange membrane.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a cross-sectional SEM image of a porous support according to an embodiment (Preparation Example 1-1) of the present invention;
2 is a cross-sectional SEM image of an anion exchange membrane according to a comparative example (Comparative Example 1) of the present invention;
3 is a cross-sectional SEM image of an anion exchange membrane according to an embodiment (Example 1) of the present invention;
4 is a cross-sectional SEM image of a porous support according to an embodiment (Preparation Example 1-9) of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in a number of different forms, and therefore is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected" with another part, this includes not only "directly connected" but also "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, this means that other components may be further provided, not excluding other components, unless specifically stated to the contrary.

Anion exchange membrane

One aspect of the present invention is _{a continuous phase matrix comprising a polyolefin having a weight average molecular weight (M w} ) of 250,000 to 450,000, and a porous support comprising a crosslinked discontinuous silane-modified polyolefin in the matrix; And an anion conductive material impregnated in the pores of the porous support or applied to the surface thereof.

The support may be a kind of porous membrane having pores formed therein. The anion conductive material may be impregnated in at least a portion of the pores inside the support, and may be further coated on at least a portion of the surface of the support. The anion conductive material inside the pores and the anion conductive material on the surface of the support may be interconnected.

In the support, the silane-modified polyolefin is crosslinked in the matrix to firmly support and fix the matrix, thereby improving the mechanical properties of the support. As used herein, the term "matrix" refers to a component constituting a continuous phase in a support including two or more components. That is, in the support _{, a polyolefin having a weight average molecular weight (M w} ) of 250,000 to 450,000 may exist in a continuous phase, and a silane-modified polyolefin crosslinked therein may exist in a discontinuous phase.

For practical use of the anion exchange membrane of the present invention, it is necessary to uniformly control the distribution of the silane-modified polyolefin so that the crosslinked silane-modified polyolefin is uniformly distributed in the support. When the crosslinking reaction of the silane-modified polyolefin occurs due to bias in some areas of the support, the required level of mechanical properties cannot be realized. Can be.

According to an embodiment of the present invention, by adjusting the molecular weight of the polyolefin constituting the matrix to a certain range, the silane-modified polyolefin is uniformly mixed in the polyolefin while the polyolefin and the silane-modified polyolefin are kneaded in an extruder. Can be dispersed. The weight average molecular weight (M _w ) of the polyolefin may be 250,000 to 450,000. If the weight average molecular weight of the polyolefin is more than 450,000, the viscosity increases and processability may be reduced, and if it is less than 250,000, the viscosity is excessively lowered to extremely lower the dispersibility of the silane-modified polyolefin, and in some cases, the polyolefin and the silane Phase separation or delamination may occur between the modified polyolefins.

The polyolefin may be one selected from the group consisting of polyethylene, polypropylene, ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and combinations or copolymers of two or more of them, and preferably, polyethylene. It is not limited.

The content of the silane-modified polyolefin in the support may be 0.1 to 5% by weight. If the content of the silane-modified polyolefin in the support is less than 0.1% by weight, the required level of mechanical properties cannot be realized, and if it exceeds 5% by weight, the mechanical properties converge to the required level, which is disadvantageous in terms of economy and productivity.

The silane may be a vinyl silane containing an alkoxy group. For example, the vinylsilane containing the alkoxy group may be one selected from the group consisting of trimethoxyvinylsilane, triethoxyvinylsilane, triacetoxyvinylsilane, and a combination of two or more of them, and preferably, trimethoxyvinylsilane, triethoxyvinylsilane, triacetoxyvinylsilane, and a combination of two or more thereof. It may be methoxyvinylsilane, but is not limited thereto.

The support may further include an inorganic filler. The inorganic filler is silica (SiO ₂ ), titanium dioxide (TiO ₂ ), alumina (Al ₂ O ₃ ), zeolite, AlOOH, barium titanate (BaTiO ₂ ), talc (Talk), aluminum hydroxide (Al (OH) ₃ ), calcium carbonate (CaCO ₃ ), and may be one selected from the group consisting of a combination of two or more of them, and preferably, spherical nanoparticles having an average particle size of 10 to 1,000 nm or 10 to 600 nm, Preferably, the surface may be a hydrophobic or hydrophilic nanoparticle. The content of the inorganic filler in the support may be 10 to 70% by weight, preferably, 10 to 60% by weight. If the content of the inorganic filler is less than 10% by weight, mechanical strength, acid resistance, chemical resistance, and flame retardancy of the support may be reduced, and if it exceeds 70% by weight, the flexibility and workability of the support may be reduced.

For example, silica (SiO ₂ ) may have a hydrocarbon layer made of hydrophobic linear hydrocarbon molecules formed on its surface. Since silica itself has hydrophilic properties, in order to improve compatibility with hydrophobic polyethylene, a spherical silica nanoparticle coated with a straight-chain hydrocarbon molecule, for example, (poly)ethylene, is suitable.

As described above, the support having a structure in which a certain amount of silane-modified polyolefin is crosslinked in a polyolefin-based matrix whose molecular weight is adjusted to a certain range may satisfy one or more of the following conditions (i) to (ix). (i) air permeability 50-300sec/100ml, preferably 125-300sec/100ml; (ii) puncture strength of 15 to 65 gf/μm, preferably, 21.5 to 65 gf/μm; (iii) longitudinal direction (MD) tensile strength 500-3,000kgf/cm ² _, preferably 700-2,000kgf/cm ² ; (iv) Transverse direction (TD) tensile strength 500-2,500kgf/cm ² , preferably 700-2,000kgf/cm ² ; (v) tensile elongation in the longitudinal direction (MD) of 40% or more, preferably, 40 to 80%; (vi) transverse direction (TD) tensile elongation of 40% or more, preferably, 40 to 55%; (vii) 20% or less, preferably 10% or less, in the longitudinal direction (MD) at 120°C; (viii) 20% or less, preferably 15% or less, of heat shrinkage in the transverse direction (TD) at 120°C; (ix) Meltdown temperature 170 to 250°C, preferably 200 to 250°C, more preferably 225 to 250°C.

The support may be hydrophilized and sulfonated to satisfy excellent ionic conductivity. The average pore size of the hydrophilized support may be 20 to 2,000 nm, _{the contact angle with moisture (H 2} O) may be 15 degrees or less, and the zeta potential measured as a negative value (-) on the surface of the porous membrane The absolute value of may be 10 mV or more, preferably 15 mV or more, more preferably 20 mV or more. In addition, the porosity of the support may be 30 to 90%, preferably, 50 to 80%.

_{The hydrophilized support has a hydrophilicity of the -SO 3} group generated on its surface and the surface of the inner pores, so it is easy with the anion conductive material due to high affinity with the anion conductive material, which is essentially hydrophilic. It can be combined together, and its bonding strength can also be strengthened, so that the durability of the anion exchange membrane can be remarkably improved, and since the loss of hydrophilic groups included in the support and the anion conductive material is minimized, ion conductivity can also be improved.

The anionic conductive material may be an aminated polymer (or an aminated polymer), and preferably, the amination degree of the aminated polymer may be 40 to 70%. As used herein, the term "degree of amination" refers to the total number of moles of a plurality of monomers constituting the aminated polymer, m, and the number of moles of a monomer substituted with at least one amine group in the aminated polymer. When is n, it can be calculated by the formula n/m. For example, if n/m is 1, the amination degree may be 100%.

In general, the higher the amination degree of the anionic conductive material, particularly the anionic conductive polymer, the higher the ionic conductivity of the polymer, while the hydrophilicity is excessively high, resulting in a phenomenon in which it is dissolved in water or severely swelled. Conversely, when the degree of amination is low, the hydrophobicity is strong, so that water resistance and durability are improved, while there is a problem that ionic conductivity is lowered. Therefore, by controlling the amination degree of the anion conductive material in the range of 40 to 70%, ion conductivity, water resistance, and durability can be implemented in a balanced manner.

The aminated polymer may have a structure represented by Formula 1 below.

<Formula 1>

In the above formula, Y is a covalent bond (-), -CO-, -SO ₂ -, or -O-, Z and D are each covalent bond (-), -O-, or -S-, and C is covalent A bond (-), -C(CH ₃ ) ₂ -, or -C(CF ₃ ) ₂ -, and R ₁ is H, or -CH ₂ N ⁺ R ₂ R ₃ R ₄ , and R ₂ , R ₃ , R ₄ is -CH ₃ , -CH ₂ CH ₃ , -(CH ₂ ) ₂ CH ₃ , -CH ₂ NH ₂ , -(CH ₂ ) ₂ NH ₂ , or -(CH ₂ ) ₃ NH(CH ₃ ) Cl, x and y are each arbitrary repeating unit, and x/(x+y) is 0.001 to 1.

For example, the aminated polymer is aminated PAES (polyaryleneether sulfone), aminated PEK (polyether keton), aminated PEEK (polyetherether ketone), aminated PS (polysulfone), aminated PES (polyether sulfone), aminated PPO (polyphenylene oxide). , aminated PPS (polyphenylene sulfide), and may be one selected from the group consisting of a combination of two or more of them, but is not limited thereto.

Method of manufacturing anion exchange membrane

Another aspect of the present invention is, (a) manufacturing a porous support by processing a composition comprising a polyolefin having _{a weight average molecular weight (M w) of 250,000 to 450,000 and a silane-modified polyolefin;} (b) crosslinking the silane-modified polyolefin contained in the porous support; And (c) impregnating the porous support in a solution containing an anion conductive material and a solvent.

In the step (a), _{a composition containing polyolefin and silane-modified polyolefin having a weight average molecular weight (M w} ) of 250,000 to 450,000 is put into an extruder, extruded, discharged through a T-die, and molded into a sheet, and then stretched. Thus, a porous support can be prepared.

The polyolefin may be one selected from the group consisting of polyethylene, polypropylene, ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and combinations or copolymers of two or more of them, and preferably, polyethylene. It is not limited.

The composition may include 20 to 40 parts by weight of the polyolefin and 0.1 to 10 parts by weight of the silane-modified polyolefin. If the content of the silane-modified polyolefin in the composition is less than 0.1 part by weight, the required level of mechanical properties cannot be realized, and if it exceeds 10 parts by weight, the mechanical properties converge to the required level, which is disadvantageous in terms of economy and productivity.

The silane may be a vinyl silane containing an alkoxy group. For example, the vinylsilane containing the alkoxy group may be one selected from the group consisting of trimethoxyvinylsilane, triethoxyvinylsilane, triacetoxyvinylsilane, and a combination of two or more of them, and preferably, trimethoxyvinylsilane, triethoxyvinylsilane, triacetoxyvinylsilane, and a combination of two or more thereof. It may be methoxyvinylsilane, but is not limited thereto.

The composition may further include 60 to 80 parts by weight of a pore-forming agent. The pore-forming agent may be extracted and removed from the inside of the support by a wet method utilizing thermally induced phase separation to form pores.

The wet method may be to immerse the support including the pore-forming agent in an extraction tank supported with a solvent. The extraction temperature may be 15 to 80°C, preferably, 25 to 40°C, and the extraction time may be 0.1 to 60 minutes, preferably 1 to 20 minutes.

The pore-forming agent is, for example, paraffin oil, paraffin wax, mineral oil, solid paraffin, soybean oil, rapeseed oil, palm oil, palm oil, di-2-ethylhexylphthalate, dibutylphthalate, diisononylphthalate, diisodecylphthalate , Bis(2-propylheptyl)phthalate, naphthenic oil, and a combination of two or more thereof may be one selected from the group consisting of, preferably, paraffin oil, more preferably, a kinematic viscosity at 40° C. of 50 to It may be 100 cSt paraffin oil, but is not limited thereto.

The solvent for extracting the pore-forming agent may be one selected from the group consisting of pentane, hexane, benzene, dichloromethane, carbon tetrachloride, methyl ethyl ketone, acetone, and a combination of two or more of them, and preferably, dichloromethane. However, it is not limited thereto.

The composition may further include a crosslinking catalyst. If the composition further includes a crosslinking catalyst, the crosslinking reaction in step (b) may be accelerated. As such a crosslinking catalyst, in general, carboxylate, organic bases, inorganic acids and organic acids of metals such as tin, zinc, iron, lead, and cobalt may be used. For example, the crosslinking catalyst is dibutyltindilaurate, dibutyltindiacetate, stannous acetate, stannous caprylate, zinc naphthenate, zinc caprylate, cobalt naphthenate, ethylamine, dibutylamine , Hexylamine, pyridine, sulfuric acid, inorganic acids such as hydrochloric acid, toluene sulfonic acid, acetic acid, stearic acid, may be an organic acid such as stearic acid, maleic acid, and the like, and preferably, dibutyltin dilaurate, but is not limited thereto.

The crosslinking catalyst has been conventionally added in the production of a silane-modified polyolefin, or a solution or dispersion of a crosslinking catalyst is applied to a support. However, it is difficult to uniformly disperse the crosslinking catalyst together with the silane-modified polyolefin by such a conventional method. As described above, before crosslinking, the silane-modified polyolefin contained in the support needs to be uniformly dispersed, and at this time, the crosslinking catalyst involved in the crosslinking reaction of the silane-modified polyolefin needs to be uniformly dispersed.

In contrast, by premixing the crosslinking catalyst with a pore-forming agent and introducing it through a side feeder of the extruder, the crosslinking catalyst is uniformly dispersed with the silane-modified polyolefin to further increase the efficiency of the crosslinking reaction.

The content of the crosslinking catalyst in the composition may be 0.01 to 5% by weight. If the content of the crosslinking catalyst is less than 0.01% by weight, the crosslinking reaction cannot be promoted to the required level, and if it exceeds 5% by weight, the reaction rate converges to the required level, which is disadvantageous in terms of economy and productivity.

The stretching performed in step (a) may be performed by a known method such as uniaxial stretching or biaxial stretching (sequential or simultaneous biaxial stretching). In the case of sequential biaxial stretching, the draw ratio may be 4 to 20 times in the horizontal direction (MD) and the vertical direction (TD), respectively, and the surface magnification accordingly may be 16 to 400 times.

In the step (b), the silane-modified polyolefin included in the porous support may be crosslinked. The crosslinking may be achieved by placing the porous support in a thermo-hygrostat in which temperature and humidity are controlled within a certain range, and in this case, the step (b) is discontinuous or continuous with the step (a). Since it is made in a moisture environment that is difficult to increase above a certain level, an excessive time may be required for the crosslinking reaction. On the other hand, in the step (b), by introducing the porous membrane into a crosslinking tank in which a solution having a boiling point of more than 100°C, preferably 120°C or more, more preferably 150°C or more is supported and continuously passing through it, the crosslinking reaction It is possible to improve productivity by significantly shortening the time required for operation.

Specifically, since the solution contains a component having a boiling point of more than 100°C, a temperature condition during the crosslinking reaction may be set to be greater than 100°C, preferably, at least 120°C to promote the crosslinking reaction. As the component, one selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, and combinations of two or more of them may be used. These components are hygroscopic and may cause a crosslinking reaction with moisture contained in the components, but if necessary, a certain amount of water may be mixed and used.

In addition, the solution may further include a crosslinking catalyst, and in this case, the crosslinking reaction may be sufficiently promoted even if a certain amount of water is not mixed. The content of the crosslinking catalyst in the solution may be 0.5 to 15% by weight. If the content of the crosslinking catalyst is less than 0.5% by weight, the crosslinking reaction cannot be promoted to the required level, and if it exceeds 15% by weight, the reaction rate converges to the required level, which is disadvantageous in terms of economy and productivity.

The crosslinking catalyst contained in the solution supported in the crosslinking tank has an effect essentially similar to that contained in the composition. However, the crosslinking catalyst included in the composition, that is, the crosslinking catalyst introduced through the side feeder of the extruder in step (a), contains a silane-modified polyolefin distributed in the center (center layer) of the porous support in step (b). While it can be crosslinked effectively, it is difficult to actively participate in the crosslinking reaction of the silane-modified polyolefin distributed in the surface portion (skin layer). The crosslinking catalyst contained in the solution supported in the crosslinking tank is in contact with the surface portion (skin layer) of the porous support when the porous support passes through the crosslinking tank, so that it is distributed on the surface portion (skin layer) of the porous support. It is possible to further accelerate the crosslinking reaction of the silane-modified polyolefin. The types and effects of the crosslinking catalyst are the same as described above.

Prior to the step (c), plasma treatment of the porous support in the presence of bromine gas, and dimolecular nucleophilic substitution reaction (S _N 2 reaction) with a compound containing an amine group; may be further included.

When preparing an anion exchange membrane to be described later through the plasma treatment and dimolecular nucleophilic substitution reaction, the surface of the porous support and the surfaces of the internal pores are hydrophilized, that is, the surfaces of the porous support and the surfaces of the internal pores have a positive charge. By making it stand out, it is possible to improve the bonding strength with the anion conductive material, and accordingly, the durability of the anion exchange membrane, in particular, long-term durability and ion conductivity can be remarkably improved.

Conventionally, in order to hydrophilize the surface of the porous support and realize a certain level of ion conductivity, a wet process in which the porous support is immersed in a reaction solution for a certain period of time to sulfonate was mainly used, but in this case, the wet process is plasma treatment. Since the plasma treatment is performed separately from the plasma treatment, such as preceding or following, the process is complicated, and there is a problem that a large amount of process waste liquid is generated.

On the other hand, since the process gas used in the plasma treatment contains bromine gas, the porous support is formed through a single dry process called plasma treatment without a wet process such as immersing the porous support in a reaction solution. It is possible to maximize the hydrophilicity and ionic conductivity of the porous support by generating bromine functional groups on the surface and on the surface of the inner pores, that is, by bromination and dimolecular nucleophilic substitution reactions, simplifying the conventional complex process, and environmental It is also advantageous from the side.

The plasma treatment may be performed for 0.5 to 90 minutes, preferably 0.5 to 20 minutes. If the plasma treatment is performed for less than 0.5 minutes, the porous support cannot be hydrophilized or brominated to a required level, and if the plasma treatment is performed for more than 90 minutes, the hydrophilicity and bromination degree converge to a certain level, resulting in a decrease in process efficiency.

_{After the plasma treatment, the porous support is subjected to a bimolecular nucleophilic substitution reaction (S N} 2) with a compound containing an amine group, for example, 1-(2-aminoethyl)piperazine (1-(2-Aminoethyl)Piperazine). Reaction), so that the surface of the porous support and the surface of the inner pores have a positive charge, thereby improving the bonding strength with the anion conductive material, thereby significantly improving the durability of the anion exchange membrane, particularly, long-term durability and ion conductivity. Can be improved.

In the step (c), the porous support may be impregnated and/or coated with a solution containing an anionic conductive material and a solvent to fill the pores of the porous support with the anionic conductive material. The anion conductive material may be coated with a predetermined thickness on the surface as well. According to step (c), the thickness of the anion exchange membrane filled and/or coated with the anion conductive material may be 30 to 200 μm.

The impregnation and/or coating may include (i) impregnating the hydrophilized porous support into an impregnation bath filled with the solution for a predetermined period of time, (ii) a coating device for delivering the hydrophilized porous support to the solution, For example, it may be made in a method of coating with a roll coater, a bar coater, or the like, or a method in which (i) and (ii) are combined.

In particular, when the step (c) is performed by using a roll coater among the (ii), the roll coater includes a first roll for transferring the solution to one side of the hydrophilized porous support and the hydrophilized porosity. A suction means of a predetermined structure and shape is mounted therein while contacting the other surface of the support to support and transport the porous support, so that the solution delivered from the first roll smoothly fits into the pores of the porous support without empty space. It may include a second roll that allows it to be filled. In addition, the solution delivered in excess of the amount required for coating is sucked by the suction means mounted inside the second roll and then transferred to a means for supplying the solution to the first roll so that the solution is reused. can do.

The content of the anion conductive material in the solution may be 10 to 60% by weight. If the content of the anion conductive material is less than 10% by weight, the ion conductivity of the ion exchange membrane may decrease, and if the content of the anion conductive material is more than 60% by weight, the ion conductivity is no longer improved, and thus unnecessary raw materials are exhausted, which is disadvantageous in terms of economy.

The anion conductive material may be an aminated polymer. The kinds and effects of the aminated polymer are the same as described above.

The solvent of the solution may be one selected from the group consisting of ester-based, ether-based, alcohol-based, ketone-based, amide-based, sulfone-based, carbonate-based, aliphatic hydrocarbon-based, aromatic hydrocarbon-based, and combinations of two or more of them, Preferably, it may be an amide-based solvent, more preferably N-methyl-2-pyrrolidone.

Examples of the ester solvent include methyl acetate, ethyl acetate, n-butyl acetate, cellosolve acetate, propylene glycol monomethyl acetate, 3-methoxybutyl acetate, methyl butyrate, ethyl butyrate, and propyl propionate. However, it is not limited thereto.

As the ether solvent, diethyl ether, dipropyl ether, dibutyl ether, butyl ethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, octyl ether, hexyl ether, etc. However, it is not limited thereto.

Examples of the alcohol-based solvent include methanol, ethanol, propanol, isopropanol, n-butanol, amyl alcohol, cyclohexanol, octyl alcohol, and decanol, but are not limited thereto.

Examples of the ketone solvent include acetone, cyclohexanone, methyl amyl ketone, diisobutyl ketone, methyl ethyl ketone, and methyl isobutyl ketone, but are not limited thereto.

Examples of the amide-based solvent include N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methylformamide, dimethylformamide, and dimethylacetamide, but are not limited thereto.

Examples of the sulfone-based solvent include dimethyl sulfoxide, diethyl sulfoxide, diethyl sulfone, and tetramethylene sulfone, but are not limited thereto.

Examples of the carbonate-based solvent include ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, propylene carbonate, ethylene carbonate, and dibutyl carbonate, but are not limited thereto.

Examples of the aliphatic hydrocarbon-based solvent include pentane, hexane, heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, and the like, and the aromatic hydrocarbon-based solvent includes benzene, ethylbenzene, chlorobenzene, toluene, Xylene, etc. may be mentioned, but the present invention is not limited thereto.

Hereinafter, an embodiment of the present invention will be described in detail. As the silane-modified polyethylene of the example, SH-100X of TSC and XHE740N of MCPP were used, respectively, or mixed, and as the silane-modified polyethylene of the comparative example, Linkron HF-700N of Mitsubishi Chemical Corporation was used.

Preparation Example 1-1

25 parts by weight of high density polyethylene (HDPE) having a weight average molecular weight (M _w ) of 350,000 and a molecular weight distribution (M _w /M _n ) of 5, 0.5 parts by weight of silane-modified polyethylene, and a kinematic viscosity of 70 at 40°C. 74.5 parts by weight of cSt paraffin oil was mixed and put into a twin screw extruder (internal diameter 58 mm, L/D=56, Twin screw extruder). The mixture was discharged from the twin-screw extruder to a T-die having a width of 300 mm under conditions of 200°C and a screw rotation speed of 40 rpm. Thereafter, a base sheet having a thickness of 800 μm was prepared by passing through a casting roll having a temperature of 40°C. The base sheet was stretched 6 times in the longitudinal direction (MD) in a roll stretching machine at 110° C., and stretched 7 times in the transverse direction (TD) in a tenter stretching machine at 125° C. to prepare a stretched film. The stretched film was impregnated in a dichloromethane leaching tank at 25° C. to extract and remove paraffin oil for 1 minute to prepare a porous membrane. The porous membrane was dried at 50°C. Thereafter, the porous membrane was heated to 125° C. in a tenter stretching machine, stretched by 1.45 times in the transverse direction (TD), and then relaxed to heat-set to 1.25 times compared to before stretching. The porous membrane was crosslinked for 72 hours in a constant temperature and humidity tank at 85° C. and 85% humidity to prepare a porous support.

Preparation Example 1-2

29.5 parts by weight of high-density polyethylene having a weight average molecular weight (M _w ) of 350,000 and a molecular weight distribution (M _w /M _n ) of 5, 0.5 parts by weight of silane-modified high-density polyethylene, and 70 parts by weight of paraffin oil having a kinematic viscosity of 70 cSt at 40°C The parts were mixed and put into a twin screw extruder (inner diameter 58 mm, L/D=56). Dibutyltindilaurate, which is a crosslinking catalyst, was pre-dispersed in some of the paraffin oil, and added through the side injector of the twin screw extruder so that it became 0.5% by weight based on the total weight of the mixture passing through the twin screw extruder. The mixture was discharged from the twin-screw extruder to a T-die having a width of 300 mm under conditions of 200°C and a screw rotation speed of 40 rpm. Thereafter, a base sheet having a thickness of 800 μm was prepared by passing through a casting roll having a temperature of 40°C. The base sheet was stretched 6 times in the longitudinal direction (MD) in a roll stretching machine at 110° C., and stretched 7 times in the transverse direction (TD) in a tenter stretching machine at 125° C. to prepare a stretched film. The stretched film was impregnated in a dichloromethane leaching tank at 25° C. to extract and remove paraffin oil for 1 minute to prepare a porous membrane. The porous membrane was dried at 50° C. for 5 minutes. Thereafter, the porous membrane was heated to 125° C. in a tenter stretching machine, stretched by 1.45 times in the transverse direction (TD), and then relaxed by 1.25 times. The porous membrane was crosslinked for 72 hours in a constant temperature and humidity tank at 85° C. and 85% humidity to prepare a porous support.

Manufacturing Example 1-3

A high-density polyethylene having a weight average molecular weight (M _w ) of 350,000 and a molecular weight distribution (M _w /M _n ) of 5 to a high-density polyethylene having a weight average molecular weight (M _w ) of 250,000 and a molecular weight distribution (M _w /M _n ) of 6 Except for the replacement, a porous support was prepared in the same manner as in Preparation Example 1-1.

Manufacturing Example 1-4

A high-density polyethylene having a weight average molecular weight (M _w ) of 350,000 and a molecular weight distribution (M _w /M _n ) of 5 to a high-density polyethylene having a weight average molecular weight (M _w ) of 250,000 and a molecular weight distribution (M _w /M _n ) of 6 Except for the replacement, a porous support was prepared in the same manner as in Preparation Example 1-2.

Manufacturing Example 1-5

The porous support was prepared in the same manner as in Preparation Example 1-1, except that the stretched film was not crosslinked in a thermo-hygrostat, but propylene glycol was added to a crosslinking bath heated to 160°C and passed through for 30 minutes in a continuous manner to crosslink. Was prepared.

Preparation Example 1-6

The stretched film is not crosslinked in a thermo-hygrostat, but a solution of propylene glycol and dibutyltindilaurate in a weight ratio of 95:5 is added to a crosslinking tank heated to 160°C, and crosslinked by passing it continuously for 10 minutes. Except for the above, a porous support was prepared in the same manner as in Preparation Example 1-1.

Manufacturing Example 1-7

The porous support was prepared in the same manner as in Preparation Example 1-1, except that the stretched film was not crosslinked in a thermo-hygrostat, and ethylene glycol was added to a crosslinking bath heated to 120°C and passed continuously for 60 minutes to crosslink. Was prepared.

Manufacturing Example 1-8

The stretched film is not crosslinked in a thermo-hygrostat, and a solution of ethylene glycol and dibutyltindilaurate in a weight ratio of 90:10 is added to a crosslinking tank heated to 120℃ and passed through for 15 minutes in a continuous manner to crosslink. Except for the above, a porous support was prepared in the same manner as in Preparation Example 1-1.

Manufacturing Example 1-9

20 parts by weight of nano-silica particles having an average particle size of 600 nm coated with ethylene, _{29.5 parts by weight of high-density polyethylene having a weight average molecular weight (M w} ) of 350,000, MFR 0.8 g/10min, trimethoxyvinylsilane having a density of 0.958 g/ml 0.5 parts by weight of modified high-density polyethylene, and 70 parts by weight of paraffin oil having a kinematic viscosity of 70 cSt at 40° C. were mixed, and nanosilica particles were dispersed using a high-speed mixer.

Then, after removing the fine bubbles generated in the mixing process through a vacuum defoaming process, it was put into a twin screw extruder (inner diameter 58mm, L/D=56). A base sheet having a thickness of 800 μm was prepared by being discharged from the twin-screw extruder to a T-die having a width of 300 mm under conditions of 200°C and a screw rotation speed of 40 rpm, and then passed through a casting roll having a temperature of 40°C. At this time, the input content was controlled so that the content of nanosilica in the base sheet was 51.4% by weight. The base sheet was stretched 6 times in the longitudinal direction (MD) in a roll stretching machine at 110° C., and stretched 7 times in the transverse direction (TD) in a tenter stretching machine at 125° C. to prepare a stretched film. The stretched film was impregnated in a dichloromethane leaching tank at 25° C. to extract and remove paraffin oil for 1 minute. The film from which the paraffin oil was removed was dried at 50° C. for 5 minutes. Then, after heating at 125°C in a tenter stretching machine, it was stretched by 1.45 times in the transverse direction (TD) and then relaxed by 1.25 times. The film was crosslinked for 72 hours in a constant temperature and humidity tank at 85° C. and 85% humidity to prepare a porous support.

Preparation Example 1-10

28.5 parts by weight of high-density polyethylene having a weight average molecular weight (M _w ) of 350,000 and a molecular weight distribution (M _w /M _n ) of 5, 1.5 parts by weight of silane-modified polyethylene, and 70 parts by weight of paraffin oil having a kinematic viscosity of 70 cSt at 40°C It was mixed and put into a twin screw extruder (inner diameter 58 mm, L/D=56). The mixture was discharged from the twin-screw extruder to a T-die having a width of 300 mm under conditions of 210°C and a screw rotation speed of 45 rpm. Thereafter, a base sheet having a thickness of 800 μm was prepared by passing through a casting roll having a temperature of 40°C. The base sheet was stretched 6 times in the longitudinal direction (MD) in a roll stretching machine at 110° C., and stretched 7 times in the transverse direction (TD) in a tenter stretching machine at 125° C. to prepare a stretched film. The stretched film was impregnated in a dichloromethane leaching tank at 25° C. to extract and remove paraffin oil for 1 minute to prepare a porous membrane. The porous membrane was dried at 50°C. Thereafter, the porous membrane was heated to 125° C. in a tenter stretching machine, stretched by 1.45 times in the transverse direction (TD), and then relaxed to heat-set to 1.25 times compared to before stretching. The porous membrane was crosslinked for 72 hours in a constant temperature and humidity tank at 85° C. and 85% humidity to prepare a porous support.

Comparative Production Example 1-1

Mix 55 parts by weight of paraffin oil with a kinematic viscosity of 70 cSt at 40°C to 45 parts by weight of silane-modified polyethylene with MFR 0.8g/10min, density 0.958g/cm ^{3 and put into a twin screw extruder (internal diameter 58mm, L/D=56)} I did. A base sheet having a thickness of 60 μm was prepared by discharging from the twin-screw extruder to a T-die having a width of 300 mm under conditions of 160°C and a screw rotation speed of 40 rpm and passing through a casting roll having a temperature of 40°C. After applying an aqueous dispersion of dibutyltindilaurate having a concentration of 30% by weight on both surfaces of the base sheet, a crosslinking reaction of silane was carried out in hot water at a temperature of 85°C for 1 hour to prepare a crosslinked film. The crosslinked film was impregnated in a dichloromethane leaching tank at 25°C to extract and remove paraffin oil for 30 minutes. The crosslinked film was dried in an oven at a temperature of 80° C. for 30 minutes to prepare a porous support.

Comparative Production Example 1-2

35 parts by weight of high-density polyethylene having a melting temperature of 135°C and a weight average molecular weight of 300,000, 65 parts by weight of paraffin oil having a kinematic viscosity of 40 cSt at 40°C, 2 parts by weight of trimethoxyvinylsilane, 2 parts by weight of dibutyltindilaurate And 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane (2,5-dimethyl-2,5-di (tert-butylperoxy) hexane) by mixing 2 parts by weight of a twin-screw extruder (internal diameter 58 mm) , L/D=56). A silane-modified polyolefin composition was prepared by reaction extrusion in the twin-screw extruder under conditions of 200°C and a screw rotation speed of 30 rpm, and discharged through a T-die having a width of 300 mm and passed through a casting roll having a temperature of 40°C to a thickness of 800 μm. An in base sheet was prepared. The base sheet was stretched 5.5 times in the longitudinal direction (MD) in a roll stretching machine at 108° C., and stretched 5.5 times in the transverse direction (TD) in a tenter stretching machine at 123° C. to prepare a stretched film. The stretched film was impregnated in a dichloromethane leaching tank at 25° C. to extract and remove paraffin oil for 10 minutes. The film from which the paraffin oil was removed was heat-set at 127° C. to prepare a porous support. The porous support was crosslinked for 24 hours in a constant temperature and humidity tank at 80° C. and 90% humidity to prepare a porous support.

Comparative Production Example 1-3

5 parts by weight of high-density polyethylene having a weight average molecular weight of 500,000, 10 parts by weight of silane-modified polyethylene having a MFR of 0.5 g/10 min and a density of 0.942 g/ml, and 85 parts by weight of paraffin oil having a kinematic viscosity of 60 cSt at 40° C. It was put into an extruder (inner diameter 58mm, L/D=56). After discharging from the twin-screw extruder to a T-die having a width of 300 mm under conditions of 160°C and a screw rotation speed of 40 rpm, passing through a casting roll having a temperature of 40°C, rolling at 115°C to obtain a base sheet having a thickness of 500 μm. Was prepared. When some defects occurred in the manufacturing process of the base sheet, it was discarded, and a base sheet having a normal appearance was selected and used.

The base sheet was stretched 3.5 times in the longitudinal direction (MD) in a 115°C roll stretching machine, and stretched 3.5 times in the transverse direction (TD) in a 115°C tenter stretching machine to prepare a stretched film. The stretched film was impregnated in a dichloromethane leaching tank at 25° C. to extract and remove paraffin oil for 1 minute. The film from which the paraffin oil was removed was dried at 50° C. for 5 minutes, and the film was crosslinked for 24 hours in a constant temperature and humidity tank at 90° C. and 95% humidity. Thereafter, heat treatment was performed at 110° C. for 30 minutes to prepare a porous support.

Comparative Production Example 1-4

A porous support was prepared in the same manner as in Preparation Example 1-1, except that the stretched film was not crosslinked in a constant temperature and humidity tank, but was added to a crosslinking tank loaded with boiling water and passed through in a continuous manner.

Comparative Production Example 1-5

A porous support was prepared in the same manner as in Preparation Example 1-1, except that the stretched film was not crosslinked in a constant temperature and humidity tank, but was added to a crosslinking tank supported by hot water heated to 80°C and passed through in a continuous manner. .

Experimental Example 1

The test method for each of the physical properties measured in the present invention is as follows. If there is no separate mention of the temperature, it was measured at room temperature (25 ℃).

-Thickness (μm): The thickness of the support specimen was measured using a fine thickness meter.

-Porosity (%): According to ASTM F316-03, the porosity of a support specimen having a radius of 25 mm was measured using a Capillary Porometer of PMI.

-Permeability (Gurley, sec/100ml): Using Asahi Seiko's Densometer EGO2-5 model, the time for 100ml of air to pass through the support specimen with a diameter of 29.8mm at a measurement pressure of 0.025MPa was measured.

-Crosslinking degree (gel fraction, %): 100mg (W ₀ ) of the support specimen was immersed in 1,2,4-trichlorobenzene and then heat-treated at 130°C for 2 hours. After the specimen was separated and dried at 50° C. for 24 hours, the weight (W) of the dried specimen was measured, and the degree of crosslinking was calculated using the following calculation formula.

-Tensile strength (kgf/cm ² ): The applied stress was measured until fracture of the specimen occurred by applying stress to a support specimen having a size of 20 × 200 mm using a tensile strength meter.

-Tensile elongation (%): Using a tensile strength meter, a stress was applied to a support specimen having a size of 20 × 200 mm, and the maximum length extended until fracture of the specimen occurred was measured, and the tensile elongation was calculated using the following calculation formula.

(In the above calculation formula, l ₁ is the length in the horizontal or vertical direction of the specimen before elongation, and l ₂ is the length in the horizontal or vertical direction of the specimen just before fracture.)

-Punching strength (gf): Using a KES-G5 model of a punching strength measuring instrument of KATO TECH, a force is applied to a support specimen of 100 × 50 mm in diameter with a stick of 0.5 mm at a speed of 0.05 cm/sec. The force applied at the time the specimen was pierced was measured.

-Meltdown temperature (°C): After applying a force of 0.01N to the support specimen using a thermomechanical analysis, the specimen was heated at a rate of 5°C/min to measure the degree of deformation of the specimen. The temperature at which the specimen breaks was taken as the meltdown temperature.

-Heat shrinkage rate (%): After placing a 200×200mm support specimen between A4 paper for 1 hour in an oven at 120°C, cooling it at room temperature, and measuring the contracted length of the specimen in the horizontal and vertical directions. The thermal contraction rate was calculated using the calculation formula.

(In the above calculation formula, l ₃ is the length in the horizontal or vertical direction of the specimen before shrinkage, and l ₄ is the length in the horizontal or vertical direction of the specimen after shrinking.)

The porous support prepared according to Preparation Example 1-2 was photographed by SEM and shown in FIG. 1. In addition, the physical properties of the support prepared according to the Preparation Example and Comparative Preparation Example were measured, and the results are shown in Tables 1 and 2 below.

division Preparation Example 1-2 (before crosslinking) Preparation Example 1-2 (after crosslinking) Thickness( μm ) 9 9.6 Porosity (%) 50 52 Air permeability (sec/100ml) 124 129 MD tensile strength (kgf/cm ² ) 1,400 1,590 MD tensile elongation (%) 85 60 TD tensile strength (kgf/cm ² ) 955 1,090 TD tensile elongation (%) 60 55 MD heat contraction rate (%) 11 5 TD heat contraction rate (%) 17 10 Drilling strength (gf) 190 230 Meltdown temperature (℃) 150 210

division Manufacturing Example 1-1 Preparation Example 1-2 Preparation Example 1-10 Comparative Production Example 1-1 Comparative Production Example 1-2 Comparative Production Example 1-3 Thickness( μm ) 9.4 9.6 9.4 25 14.3 26 Porosity (%) 50 52 46 43 33 42 MD tensile strength (kgf/cm ² ) 1,520 1,590 1,740 779 1,350 2,137 MD tensile elongation (%) 67 60 58 173 210 47 TD tensile strength (kgf/cm ² ) 1,020 1,090 1,350 543 1280 1,793 TD tensile elongation (%) 52 55 48 159 183 33 MD heat contraction rate (%) 7 5 3 12 11 17 TD heat contraction rate (%) 11 10 7 14 13 19 Drilling strength (gf) 210 230 360 150 480 350 Meltdown temperature (℃) 205 210 225 177 190 185

Experimental Example 2

The paraffin oil regenerated after extraction in the dichloromethane leaching tanks of Preparation Example 1-2 and Comparative Preparation Examples 1-1 and 1-2 was subjected to inductively coupled plasma atomic emission spectroscopy (ICP), and the results were obtained. It is shown in Table 3 below.

division Si content (mg/kg) Sn content (mg/kg) Remark Preparation Example 1-2 5 3 Within measurement error Comparative Production Example 1-1 4~5 1~2 Within measurement error Comparative Production Example 1-2 220 7 -

Referring to Table 3, in Preparation Example using a silane-modified polyolefin and Comparative Preparation Example 1-1, the Si content per 1 kg of paraffin oil is 5 mg or less within the measurement error, but Comparative Preparation Example 1 using trimethoxyvinylsilane 2, 220 mg of Si was detected per 1 kg of paraffin oil. In addition, as a result of additional analysis of the paraffin oil of Comparative Preparation Example 1-2, it was confirmed that a number of silanes were grafted to paraffin oil other than polyethylene during the grafting process of trimethoxyvinylsilane. The silane-modified paraffin oil was completely discarded because it was not regenerated.

Experimental Example 3

The porous support prepared according to Preparation Example and Comparative Preparation Example was divided into three portions in the transverse direction (TD), and the support specimen was extracted from each portion, and the degree of crosslinking, the puncture strength, and the meltdown temperature were measured and shown in Table 4 below. In Table 4 below, L denotes a value measured on a specimen of the support on one side, R on the other side, and M on the center side. The maximum difference is the greater of the difference between the M value and the L or R value.

division Preparation Example 1-2 Manufacturing Example 1-4 Comparative Production Example 1-2 Comparative Production Example 1-3 L Drilling strength (gf) 250 240 490 230 M Drilling strength (gf) 230 220 450 410 R punching strength (gf) 220 230 470 490 Maximum difference (gf) 30 20 40 260 L meltdown temperature (℃) 211 224 193 212 M meltdown temperature (℃) 208 215 179 157 R meltdown temperature (℃) 207 219 187 149 Maximum difference (℃) 4 9 14 63

Experimental Example 4

When crosslinking according to Preparation Examples and Comparative Preparation Examples, the gel fraction of the support according to the crosslinking time was measured to evaluate the reaction rate according to the crosslinking method and conditions, and the results are shown in Table 5 below.

Crosslinking time Manufacturing Example 1-5 Preparation Example 1-6 Comparative Production Example
1-4 Manufacturing Example 1-7 Manufacturing Example 1-8 Comparative Production Example
1-5 2 30 34 0 - - - 5 42 69 4 5 20 0 10 55 70 12 12 48 0 15 65 - 25 20 61 5 30 70 - 50 42 - 6 45 - - 70 - - - 60 - - - 60 - 11

Referring to Table 5, in the case of Preparation Examples 1-5 and 1-6 in which the crosslinking reaction was carried out continuously in a crosslinking tank carrying propylene glycol (boiling point: 188.2°C), about 70 compared to Comparative Preparation Example 1-4. The time required to achieve the degree of crosslinking of% was reduced to a maximum of 1/3 or less, and the crosslinking reaction was carried out in a continuous manner in a crosslinking tank in which ethylene glycol (boiling point: 197.3°C), which has a higher boiling point than propylene glycol, was supported. In the case of 1-7 and 1-8, the time required to achieve a degree of crosslinking of about 60% was reduced to a maximum of 1/10 or less compared to Comparative Preparation Example 1-5.

Manufacturing Example 2

In order to modify the surface of the porous support of Preparation Examples 1-1 to 1-8, it was treated with vacuum plasma. Before plasma treatment, the porous support was inserted into a frame that can be kept flat and purged with nitrogen to remove impurities on the support.

The chamber size of the apparatus for vacuum plasma treatment is 420mm in width, 430mm in depth, and 270mm in height, and a planar electrode for generating plasma was used having a structure in which the ground electrode and the AC applying electrode alternately consist of six stages. The porous support was placed in parallel with the electrode plate at a point 2 mm away from the electrode at the 2nd, 3rd, and 4th stages from the lowermost electrode, and a vacuum condition was created until the pressure inside the chamber became 0.1 torr.

_{A bromine gas (Br 2} , process gas) having a composition according to Table 6 below was introduced into the chamber at a flow rate of 30 sccm, and the pressure inside the chamber was maintained at 0.2 torr for 2 minutes and purged. In addition, a high-frequency power having a frequency of 13.56KHz was applied at an output of 300W to create a plasma condition inside the chamber for 2 minutes, so that a bromine functional group was attached to the porous support.

The upper and lower surfaces of the porous support were turned over and placed in the chamber in the same manner as described above, and the same process was repeated to ensure that both surfaces of the porous support, that is, the upper and lower surfaces, were evenly treated with plasma.

In order to replace the bromine functional group bonded to the plasma-treated porous support with an amine group, S _N 2 reaction (bimolecular nucleophilic substitution reaction, Bimolecular Nucleophilic Substitution) was performed for 48 hours at each of the materials listed in Table 6 below, temperature, and atmospheric pressure conditions. Then, it was washed with ethanol and distilled water. Thereafter, for stable ionization of functional groups, 20 wt% methyl iodide (Iodomethane, CH ₃ I), 80 wt% n-butanol (n-butanol, CH ₃ (CH ₂ ) ₃ OH) solution at 35° C., atmospheric pressure The reaction was carried out at for 48 hours to quaternize the amine group.

Experimental Example 5

The surface of the porous support prepared in Preparation Example 1-1 was modified by plasma and post-treatment, and the zeta potential (mV) of the surface was measured using a flow potential method to quantify the charge characteristics of the modified surface. , The results are shown in Table 6 below.

division Comparative Production Example 2-1 Comparative Production Example 2-2 Manufacturing Example 2-1 Manufacturing Example 2-2 Process gas - Br ₂ 100% Br ₂ 100% Br ₂ 100% S _N 2 reactant - - 1-(2-Aminoethyl) Piperazine(C ₆ H ₁₅ N ₃ ) 1-(2-Aminoethyl) Piperazine
(C ₆ H ₁₅ N ₃ ) S _N 2 reaction temperature - - 25℃ 25℃ Presence or absence of sagaization reaction radish radish radish U Wettability Bad Bad Good Good Zeta potential (mV) 0 0 +24.25 +27.76

Referring to Table 6, the _{porous support (Comparative Preparation Examples 2-1 and 2-2) that did not undergo plasma surface treatment and/or SN} 2 reaction was very hydrophobic and the surface was not charged at all, whereas bromine plasma In the case of Preparation Examples 2-1 and 2-2 subjected to treatment and S _N 2 reaction, it can be seen that the surface has a positive charge and is remarkably converted to hydrophilicity.

In particular, it can be seen that the zeta potential of the porous support of Preparation Example 2-2, which has undergone a tetravalent reaction, is higher than that of Preparation Example 2-1, and through this, stable ionization is possible due to the tetravalentization of the amine group.

Preparation Example 3: Preparation of aminated PAES (polyaryleneethersulfone)

A gas inlet, thermometer, Dean-Stark trap, cooler and stirrer were installed in a 100 mL round flask, and after removing air and impurities for several minutes in a nitrogen atmosphere, 4,4'-dichlorodiphenylsulfone 3.4460 g, 4 ,4'-biphenol (BP) 3.7242 g, disulfonated dichlorodiphenyl sulfone 3.9301 g, K ₂ CO ₃ 3.1787 g and NMP 44.4 mL, toluene 22.2 mL (NMP/toluene = 2/1, v/v) was added And, the monomer was dissolved while stirring at 80° C. or higher for 1 hour.

Thereafter, after raising the temperature of the reaction solution to 160°C, refluxing with toluene for 4 hours to remove water as the reaction product, and then raising the temperature to 190°C to completely remove residual toluene in a Dean-Stark trap and react for 24 hours. Made it. When the reaction was completed, the reaction solution was diluted with NMP, filtered, poured into water, precipitated in the form of swollen fibers, and filtered. Thereafter, the obtained reaction product was dried in a vacuum dryer at 120° C. for 24 hours to obtain a polymer polymer.

100 g of the obtained polymer was added to a 1 L 4-neck flask after installing a mechanical stirrer, a gas inlet, a condenser, and a thermostat for temperature setting. Thereafter, 1,1,2,2,-tetrachloroethane (TCE, 1,1,2,2-tetrachloroethane) was sufficiently dissolved so that the polymer was 12.8% by weight based on 425.8 mL. The thermostat was set to 40°C, _{8.233 g of the reaction catalyst ZnCl 2} was added, stirred for 30 minutes, and then 103.0 mL of chloromethylmethylether (CMME) was added through a dropping funnel.

The amount of chloromethylmethyl ether added was calculated as 5 times the number of moles of CMME reacted per unit mole number and added.

After vigorous reaction for 4 hours while injecting dry inert gas through the gas inlet, the product was filtered and precipitated in excess methanol, and the precipitated chloromethylated polyarylene ethylene sulfone was pulverized and washed several times with ethanol and deionized water. The washed chloromethylated polyarylene ethylene sulfone was dried in a vacuum oven at 90° C. for 12 hours or more.

200 g of the prepared chloromethylated polyarylene ether sulfone was placed in a 2L 4-neck flask equipped with a mechanical stirrer and dissolved in 1489.4 mL of dimethylacetamide (DMAc, N,N-dimethylacetamide) at 12.5% by weight. When 366 mL of trimethylamine is added dropwise to the reactor using a dropping funnel, the input amount is 4 times the number of moles of trimethylamine (TMA) reacting per mole of chloromethylated polyethersulfone repeating units, and reacted for 12 hours to conduct anionic conductivity A material solution was prepared.

Example 1

The porous support of Preparation Example 1-1 was subjected to plasma treatment according to Preparation Example 2-2, and then impregnated with the anion conductive material solution prepared in Preparation Example 3 to prepare an anion exchange membrane.

Example 2

An anion exchange membrane was prepared in the same manner as in Example 1, except that a support not subjected to plasma treatment was used.

Comparative Example 1

A commercially available Neosepta ^TM anion exchange membrane (AMX) was washed with deionized water to prepare an anion exchange membrane.

Experimental Example 6

The performance and durability of the prepared anion exchange membrane were evaluated by the following method, and the results are shown in Table 7 below.

-Ion conversion rate (IEC, meq/g): After immersing the sample in NaCl solution using the Mohr titration method to measure the ion exchange capacity, the quaternary ammonium group is completely substituted in the form of ^{-N +} (CH ₃ ) _{3 Cl} , When immersed in _{0.5M Na 2} CO ₃ ^{solution again and replaced with N +} (CH ₃ ) ₃ CO ₃ ^- , and 1 to 2 drops of 5% potassium dichromate solution are added dropwise to this solution, when red-brown precipitation occurs with _{AgNO 3 To calculate the amount of AgNO 3} consumed by dropwise addition, the ion exchange capacity of the anion exchange membrane was calculated by the following equation.

Here, W _dry is the weight of the dried film, V _AgNO3 is the volume of AgNO ₃ consumed, and C _AgNO3 is the concentration of the _{AgNO 3} solution used in the titration.

-Water absorption rate (water uptake, %): To measure the water absorption rate of the anion exchange membrane, the anion exchange membrane was washed several times with deionized water, and the washed anion exchange membrane was immersed in deionized water for 24 hours. After removing the water, the weight (W _wet ) was measured. Subsequently, the same anion exchange membrane was dried again in a vacuum dryer at 120° C. for 24 hours, and then the weight (W _dry ) was measured again, and the water absorption rate was calculated using the following equation.

-Dimensional stability (ΔΔΔ%): Dimensional stability is the same as the water absorption rate measurement method, but instead of weight, the length, thickness, and volume change of the anion exchange membrane were measured, and the dimensional change rate was calculated using the following equation.

-Membrane resistance (Resistance, Ω.cm ² ): For the anion exchange membranes prepared in Examples and Comparative Examples, electrical resistance was measured using a measuring equipment (Neoscience VSP-300 Impedance/Gain-phase analyzer). Electrical resistance was measured by the AC impedance measurement method. After the anion exchange membrane was sufficiently immersed in 2M NaCl solution, the electrical resistance was measured using a clip cell.

Resistance(Ω.cm ² ) = (r ₁ -r ₂ ) * S

Where r ₁ is the measured resistance value and r ₂ is the resistance value when there is no film. S is the area (cm ² ) of the clip cell.

division Water absorption rate Ion conversion rate Film thickness Membrane resistance Δl Δt ΔV Example 1 10.11 2.07 30 1.62 1.17 1.87 4.25 Example 2 20.20 1.75 30 4.55 2.17 2.24 6.14 Comparative Example 1 24.50 1.38 140 3.24 4.54 4.60 14.40

Referring to Table 7 above, in the case of the anion exchange membrane obtained using the porous support of Preparation Example 1-1 regardless of plasma treatment, the water absorption rate and the ion conversion rate were superior to that of the commercial anion exchange membrane of Comparative Example 1, and in particular, The dimensional stability has been greatly improved.

Comparing the results of Examples 1 and 2, the anion exchange membrane of Example 1, prepared by impregnating a plasma-treated porous support with an anion conductive material, has an ion conversion rate of about 2.0 meq/g or more, and a porous support not subjected to plasma treatment. Compared to the anion exchange membrane of Example 2, which was prepared by impregnating an anion conductive material, the ion exchange capacity was excellent, and the dimensional stability was improved.

In addition, referring to FIG. 3, it can be seen that the anion exchange membrane of Example 1 is uniformly impregnated with an anion conductive material therein, and accordingly, the water absorption rate is also lower than 15%, and durability as an anion exchange membrane is also excellent.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that other specific forms can be easily modified without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

Claims (10)

A porous support comprising a continuous phase matrix comprising a polyolefin having a weight average molecular weight (M _w ) of 250,000 to 450,000 and a discontinuous silane-modified polyolefin crosslinked in the matrix; And
Including; anion conductive material impregnated in the pores of the porous support or applied to the surface,
The content of the silane-modified polyolefin in the porous support is 0.1 to 5% by weight, an anion exchange membrane. delete The method of claim 1,
The silane is a vinyl silane containing an alkoxy group, an anion exchange membrane. The method of claim 1,
The anion conductive material is an aminated polymer, an anion exchange membrane. The method of claim 4,
The aminated polymer has the structure of the following formula (1), anion exchange membrane:
<Formula 1>

In the above formula,
Y is a covalent bond (-), -CO-, -SO ₂ -, or -O-,
Z and D are each a covalent bond (-), -O-, or -S-,
C is a covalent bond (-), -C(CH ₃ ) ₂ -, or -C(CF ₃ ) ₂ -,
R ₁ is H, or -CH ₂ N ⁺ R ₂ R ₃ R ₄ ,
R ₂ , R ₃ , R ₄ are each -CH ₃ , -CH ₂ CH ₃ , -(CH ₂ ) ₂ CH ₃ , -CH ₂ NH ₂ , -(CH ₂ ) ₂ NH ₂ , or -(CH ₂ ) ₃ NH(CH ₃ )Cl,
x and y are each arbitrary repeating unit,
x/(x+y) is 0.001-1. The method of claim 4,
The aminated polymer is aminated PAES (polyaryleneether sulfone), aminated PEK (polyether keton), aminated PEEK (polyetherether ketone), aminated PS (polysulfone), aminated PES (polyether sulfone), aminated PPO (polyphenylene oxide), aminated PPS ( polyphenylene sulfide) and one selected from the group consisting of a combination of two or more of them, an anion exchange membrane. The method of claim 1,
The porous support further comprises an inorganic filler,
The content of the inorganic filler in the porous support is 10 to 70% by weight, anion exchange membrane. (a) manufacturing a porous support by processing a composition comprising 20 to 40 parts by weight of a polyolefin having a weight average molecular weight (M _{w) of 250,000 to 450,000 and 0.1 to 10 parts by weight of a silane-modified polyolefin;}
(b) crosslinking the silane-modified polyolefin contained in the porous support; And
(c) impregnating the porous support in a solution containing an anion conductive material and a solvent; Including,
In the product of step (b), the polyolefin and the crosslinked silane-modified polyolefin constitute a continuous phase and a discontinuous phase, respectively. The method of claim 8,
Before step (c),
Plasma treatment of the porous support in the presence of bromine gas, and dimolecular nucleophilic substitution reaction (S _N 2 reaction) with a compound containing an amine group; further comprising, a method of manufacturing an anion exchange membrane. The method of claim 9,
The plasma treatment is performed for 0.5 to 90 minutes, the method of manufacturing an anion exchange membrane.

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