JPS6026142B2 - Method for manufacturing ion exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to chemical resistance obtained by uniformly mixing and molding a fluorine-containing anionic polymer electrolyte or its derivative and a finely powdered inorganic ion exchanger.

Ion exchangers are widely used industrially as a separation technique without phase change in various fields. For example, granular ion exchangers are widely used as deionizing agents and adsorbents in water treatment, and have a wide range of other uses such as catalysts and purification of pharmaceuticals. Membrane-like materials are also used as ion exchange membranes in electrodialysis, diffusion dialysis, and electrode reaction membranes, and are also used as ultrafiltration membranes and reverse osmosis membranes. Other ion exchangers in various shapes, such as fibrous materials and tubular materials, have been researched, developed, and proposed. The merits and demerits of various ion exchangers that carry out the above-mentioned ion exchange phenomenon are determined by their functions, and those with better functions and more unique functions promise a wider range of applications. It is.

For this reason, even though various technologies using ion exchange phenomena have been industrialized today, their improvements are constantly being made. The present inventors have also conducted research and development on ion exchangers to date, and have proposed various ion exchangers with unique functions and ion exchangers with more functions. From this point of view, the inventors further conducted research and found that
A fluorine-containing anionic polymer electrolyte with a non-crosslinking exchange capacity of 0.3 milliequivalents/g dry polymer (Nippon type) or more or its concession, and an inorganic ion exchanger with an average particle size of 100 microns or less. The present invention proposes a method for producing a composite ion exchanger, which is characterized in that the mixture is uniformly mixed and then molded, and if necessary, an anion exchange functional group is introduced.

Conventionally, ion exchangers have been produced by heating and pressurizing an inorganic ion exchanger into a plate shape, by heating and molding an inorganic ion exchanger with a stable fluorine-based polymer into a membrane or granule shape, and by inorganic ion exchangers. Various methods have been proposed, including a method of making a membrane-like ion exchange membrane from an ion exchanger and asbestos. Membranes obtained by forming plates using only the above-mentioned inorganic ion exchanger have low mechanical strength, and those solidified into granules have a slow ion exchange rate. Furthermore, in the method of molding inorganic ion exchanger fine powder together with other sulfur-containing sulfur-containing polymers into granules or membranes, the sulfur-containing sulfur-containing polymers used as binders have no ion exchange properties. The inorganic ion exchanger becomes diluted, which limits the performance of the ion exchanger. Furthermore, ion exchange membranes made of inorganic ion exchangers and asbestos cannot be used under normal conditions because the solution inevitably flows through the membrane due to water pressure. Furthermore, JP-A-51-112-783 and JP-A-52-8997 disclose a method of impregnating a fluorine-containing cation exchange membrane with an inorganic substance or an inorganic ion exchanger. However, it is extremely difficult for ions with the same sign as the ion-exchange groups of the ion-exchange membrane to enter the intestinal ion-exchange membrane in order to exclude Donnan, so it is actually difficult to allow them to penetrate into the parent ion-exchange body. All that is possible is the same amount of counter ion as the total ion exchange state of the ion exchanger. Even if this is precipitated to form an inorganic ion exchanger, it will only produce an inorganic ion exchanger within the parent ion exchanger that has at most the same ion exchange ability as the parent ion exchanger; It is not possible to have a larger amount of inorganic ion exchanger present in the ion exchanger by the method described above. As described above, ion exchangers using conventional inorganic ion exchangers have drawbacks, and have been unable to fully exhibit the functions of both the organic ion exchanger and the inorganic ion exchanger. However, according to the present invention, it is possible to integrate a large amount of inorganic ion exchanger of 3% by weight or more with organic ion exchanger, so that the heat resistance, oxidation resistance, and organic solvent resistance of the inorganic ion exchanger can be improved. It has excellent properties such as radiation resistance, resistance to organic contamination, selective permselectivity for special ions, and has excellent ion exchange function.
In particular, it is possible to provide an industrially useful composite ion exchanger.

The present invention uses a non-crosslinkable, fluorine-containing anionic polymer electrolyte or derivative thereof having an exchange capacity of 0.3 meq/g dry polymer (Japanese type) or more, and an inorganic polymer with an average particle size of 100 microns or less This is a method for manufacturing a composite ion exchanger by mixing and melt-molding an ion exchanger.

In particular, the majority of the entire ion exchange chamber of the composite ion exchanger can be made up of inorganic ion exchangers, thereby further improving heat resistance, oxidation resistance, organic solvent resistance, radiation resistance, etc. Becomes a good ion exchanger. In the present invention, the non-crosslinkable fluorine-containing anionic polymer electrolyte or its derivative, which is the raw material of the composite ion exchanger, contains a negatively charged functional group or a functional group that can be easily converted thereto, and a fluorine atom. There is no particular restriction as long as it is uniformly combined.

Examples of negatively charged functional groups include sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphorous acid groups, phosphate ester groups, phosphite ester groups, sulfate ester groups, phenolic hydroxyl groups, thiol groups, and dissociated groups. The functional group is one or more of the functional groups that dissociate in an aqueous solution or a water-organic mixed solvent to give a negative charge, such as an acid amide group having a hydrogen atom that can be used, or a metal chelate compound that can give a negative charge. In addition, examples of derivatives that can be converted into anionic functional groups include the above-mentioned Hyakkan group ester,
There is no restriction at all as long as it can be easily converted into an anionic functional group such as acid halides, acid anhydrides, and others. In addition, the fluorine atom bonded to the polymer electrolyte is preferably in a position that stabilizes the ion exchange group, and is particularly preferably bonded to the carbon at the position of the ion exchange group.
Furthermore, a perfluorinated polymer electrolyte is preferable. Furthermore, in order to mold the fluorine-containing polymer electrolyte into a certain shape with the inorganic ion exchanger, it must be thermoplastic or be dissolved in an appropriate solvent, and it must be non-crosslinkable and non-aqueous. is preferred. Specific examples of fluorine-containing anionic polymer electrolytes include ethylene tetrafluoride, ethylene trifluoride-chloride, ethylene trifluoride, vinylidene fluoride, propylene hexafluoride, /fluoroalkylthioether, / CF2=CFORfA, CF2=CFRfA, CF2 with one or more fluoroalkyl pinylethers, etc.
=CFA {However, Rf is −C cape 2n+m−, (C cape 2n
10 mol) p is a chain, branched, cyclic, saturated, or unsaturated perfluoro group, A is -SQB, -COB, -CN, -P (however, B is a halogen, OH, OR, OM
, NR2R3, R is an alkyl group having 1 to 16 carbon atoms, R
2, R3 is a hydrogen atom, R, , M are metal ions, organic ions (n, m, 1, p are positive integers), or a multicomponent copolymer.

Note that the exchange capacity of the fluorine-containing anionic polymer electrolyte or its derivative as an anionic polymer electrolyte is 0.
A range of 3 milliequivalents/gram dry polymer (Japan type) or more is desirable. If the exchange capacity is less than 0.3 milliequivalents/gram dry polymer (Japan type), there is an effect as an intestinal ion exchange group, but it is extremely weak, and it is more than 0.3 milliequivalent/gram dry polymer (Japanese type). In these cases, the composite ion exchanger obtained by the present invention exhibits particularly remarkable effects. Next, the inorganic ion exchanger to be mixed with the fluorine-containing anionic polymer electrolyte may be cation exchangeable, anionic exchangeable, or strongly acidic, weakly acidic, strongly basic, or weakly basic. However, the composite ion exchange membrane that is often manufactured may be appropriately selected depending on the purpose of use.

Specific examples of the above inorganic ion exchangers include zirgonium phosphate, zirconium silicate, zirconium stannate, zirconium tungstate, cerium phosphate, titanium arsenate, tin antimonate, etc., which exhibit intestinal ion exchange properties. As represented, Mb○y(Pz○w)・n
It has a structure of ratio ○, where x, y, n, z, and w are integers, and M is Zr, Ti, Sn, Th, U, cerium,
Niobium, tartan, etc. (PzOW) are generally phosphoric acid, arsenic acid, antimonic acid, vanadic acid, molybutenic acid, tungstic acid, oxalic acid, boriphosphoric acid, etc. Hydroxides and hydrous oxides are also effective. That is, general formula M illusion y female 2
0 (x, y, n are positive integers), and examples of intestinal ion exchange properties include Mm40, Nb50, T
There are a50, Sb50, Si40, Mo60, etc., and those showing anion exchange properties include Cd20, Cu20, Z
〆+, Mg20, Bi3↓, Sge10, ku30, etc. Those exhibiting the behavior of amphoteric ion exchangers are Mr20, &30, N30, Fe30, Mn30, ln30, Th4. Ten,
These include hydroxides and hydrated oxides such as Be40, Z+, Sn40, and Ti40. These can become dominant ion exchangers, anion exchangers, or amphoteric ion exchangers depending on the usage conditions of the solution. Basic salts and complex hydroxides are used as anion exchangers. Examples of basic salts are CM, $u(OH)2, Misaki20 (X is S042
-, CI-, NQ-, CI04-, etc.), Pb (N02
) Snake b(OH)2, Zn(N02)・nZn(OH)2
There are complex hydroxides such as CIn[AI2-n
Cn403] Milk day 20 (C40 is Ti40, Zr4
10, Si40), CIn [2n (11n) AIn○] Nagi○, etc. Hete again. Examples of polyacid salts include those represented by 2XY, 2Qo·mH20 (X is P, As, Snake, Si, etc.; Y is Mo, W, V, etc.), such as ammonium molybdophosphate and ammonium tungstophosphate. Cyanide keys can also be used as ion exchangers, and are represented by the general formula M[Y(CN)6], where M is an alkali metal ion, hydrogen ion, and x is Zn, Cu, Ni, Mn, Cd, Fe(
m), heavy metals such as Ti, W03, Moo3, Y is Fe
(b), Fe(m). Co(0) and the like are used, such as ferrocyanide steel, nickel ferrocyanide, and zinc ferrocyanide. Alternatively, if either Na20-AI2Q gel or Si02 gel is used to form a sphere or membrane, and then the other is impregnated and heat treated, a zeolite-type inorganic ion exchanger is produced within the ion exchanger.

The same can be said about AI203 gel and Si02 gel. Further, fine powders of metals and fine powders of metal oxides that can form inorganic ion exchangers can also be used. These can be made into inorganic ion exchangers by mixing with anionic polymer electrolytes and forming them into ion exchangers of a certain shape, or by reacting with acids, alkalis, or other suitable organic or inorganic reagents before or after forming them. . Although some examples of inorganic ion exchangers used in the present invention have been described above, the present invention is not limited to the above examples, and the present invention is not limited to any inorganic ion exchanger having cation exchange properties, anion exchange properties, or amphoteric ion exchange properties. More than one type of exchanger can be used without any restriction.

Furthermore, when intestinal ion exchangers and anion exchangers coexist, as is well known, both may be distributed uniformly within the ion exchanger, or the layers containing each ion exchange group may be layered. The layered structure may not be limited to two layers, but may be formed into a large number of layers.

That is, layers of ion-exchange groups with different charges may be present in the form of a sandwich. Either one of the charged layers may be extremely thicker or thinner than the other, or may have the same thickness. Alternatively, inorganic ion exchangers may be present in a mosaic pattern in the anionic polymer electrolyte.
It is desirable that these inorganic ion exchangers are dispersed as uniformly and finely as possible within molded ion exchangers of various shapes such as spherical, granular, filamentous, fibrous, and tubular.

Therefore, it is desirable that the particle size of the inorganic ion exchanger used be as fine as possible, and particularly when the particle size is about 100 microns or less, a good ion exchanger can be obtained. For example, in the case of a membrane-like material, electrochemical properties such as ring ratio and electrical resistance are significantly improved by uniformly distributing ion exchange groups. Next, as a means of forming a non-crosslinkable fluorine-containing anionic polymer electrolyte and an inorganic ion exchanger into granules, pockets, or other specific shapes, a fluorine-containing linear anion-exchange polymer electrolyte is a thermoplastic In this case, a low-molecular compound or a high-molecular compound such as an oligomer of trifluorochloroethylene or a copolymer of tetrafluoroethylene and propylene can be used as a plasticizer. They may be mixed.

The ion exchanger obtained by the present invention can be used for various purposes such as ion exchange reactions, electrodialysis, diffusion dialysis, Donnan dialysis, membranes for electrode reactions, liquid chromatography, and catalysts, depending on its shape. It is suitable for use in atmospheres that require chemical resistance because it is a polymer-based material and an inorganic ion exchanger.

In addition, since an inorganic ion exchanger is used, it is suitable for use in an atmosphere where radiation is present, but since fluorine-containing polymers are generally decomposed by radiation, inorganic ion exchangers are less effective than fluorine-containing polymer electrolytes. It is desirable to increase the body content within a range that does not reduce mechanical strength. In the present invention, it is essential to form an ion exchanger using a non-crosslinked anionic polymer electrolyte or its derivative, but it is preferable that the ion exchanger obtained has a crosslinked structure. There are cases.

In this case, 1) heating is performed in the presence of an organic peroxide; 2
) Irradiation with radiation, electron beams, or X-rays in the presence of organic peroxides.

3) Simply irradiate with radiation, electron beams, or X-rays.

4) Irradiating radiation, electron beams, or X-rays in the presence of vinyl, allyl, acetylene compounds, etc. or their polymers.

Conventionally known crosslinking means such as contacting with a vinyl, furyl, acetylene compound, etc. after carrying out steps 5) and 3) can be used without any restriction.

The vinyl, allyl, acetylene compounds, etc. used in this case are preferably fluorine-containing compounds from the viewpoint of chemical resistance.
One or more types of ion-exchangeable groups or groups that can be easily converted into ion-exchangeable groups, and anion-exchangeable groups or groups that can be easily converted into ion-exchangeable groups can be used without restriction. For example, ethylene tetrafluoride, ethylene trifluoride-chloride, vinylidene fluoride,
Ethylene trifluoride, vinyl fluoride, perfluoropropylene, perfluorobutadiene, etc., or perfluorosulfonic acid or zero salt esters, perfluorosulfonyl halides, perfluoroalkyl vinyl ethers, or /fluoroalkyl vinyl Preferred are ether containing sulfonic acid, carboxylic acid, phosphoric acid, phosphorous acid, or a compound having a functional group that can be easily converted into these, Z-fluoroacrylic halide, perfluoroacrylic acid, and the like.

In addition, when forming crosslinks on this ion exchanger after molding, depending on the degree of crosslinking formation, a water-lacquer-like fluorine-containing anionic polymer electrolyte or a derivative thereof may also be used. Although the present invention has been briefly explained above, the following examples are given to explain the present invention more specifically. Note that the content of the present invention is not limited in any way by the following examples. In the examples, since an ion exchange membrane was formed for the membrane-like material, its electrochemical properties were measured. That is, the electrical resistance of the membrane is 0. Arc-10 in NaCI
Measured at 260 by 00 cycles AC. The barrier ratio of the membrane is 0. State-NaCI and 2. A membrane was placed between the arc and NaCI, and the transference number was calculated using the Nernst equation from the pus potential generated therebetween. In addition, the ion exchange capacity when using an ion exchange resin was measured by the same method as when measuring the cross capacity of an ordinary ion exchange resin. Example 1 When an ion exchanger is obtained by hydrolysis with a copolymer of tetrafluoroethylene and perfluoro(3,6-dioxer-4-methyl-7-octensulfonyl fluoride), the exchange capacity is 0.83 milliequivalent/ Gram resin (Japanese type)
Six parts by weight of a fine powder equivalent to the above and four parts by weight of a fine powder of zirconium phosphate having an average particle size of 10 microns or less were uniformly mixed.

Zirconium phosphate is 1. Zirconium oxychloride is dissolved in hydrochloric acid, and P04/Zr is added at an equivalent ratio of 2. Phosphoric acid was added to make a needle sound. A precipitate of zirconium phosphate was obtained. After passing through, washing with water and drying, the powder was ground in a mortar and classified to particles of 10 microns or less. This had an exchange capacity of 0.7 meq/night. Both are about 32
The mixture was melt-mixed using heating rolls at 0° C. to mix as uniformly as possible, then shaped into pellets, cooled with liquid oxygen, and ground into fine powder in an agate mortar.

This was sandwiched between two aluminum plates, and pressed in a press at 310° C. and 60k9/metre. At this time, in order to control the thickness of the film, a polytetrafluoroethylene plain-woven fabric in which 60 100-denier threads were inserted both vertically and horizontally was sandwiched between the aluminum foils. . The resulting membrane was soaked in a hydrolysis bath consisting of a 10% NaOH solution in ethyl alcohol.
The sulfonyl fluoride group was hydrolyzed to sodium sulfonate.

As a result, a cation exchange membrane having both phosphoric acid groups and sulfonic acid groups was obtained. The electrical resistance of the membrane is 2.10, the cation ring ratio is 0.86%, and the thickness of the membrane is 0.15.
It was on the side. Example 2 The exchange capacity when hydrolyzed into a carboxylic acid with a copolymer with
．． 60 parts of fine resin powder equivalent to 2 milliequivalents/gram dry resin (Nippon Type) and four bases of zirconium tungstate with a particle size of 1 or less and an exchange capacity of 2.2 milliequivalents are uniformly mixed, and the mixed fine powder is The powder was placed evenly between two aluminum sheets with a plain-woven cloth in which 50 400-denier polytetrafluoroethylene threads were inserted both vertically and horizontally, and then this was placed between an iron plate. Pressure molding was performed at a pressure of 100k9/cm.

At this time, the iron mold was heated to 150° C. to melt the copolymer and integrate it with the inorganic ion exchanger to form a film-like product. Next, this film-like material was immersed in a methanol solution of 10% caustic soda for 6 hours to hydrolyze the ethylene fluoride in the pus to form sodium carboxylate. The electrical resistance of this membrane is 3.20, the ion resistance is 0.87, and the thickness of the membrane is 0.20. It was Matsuhata. Example 3 Tetrafluoroethylene and perfluoro(3,6-dioxa-4-methyl-7-octensulfonyl fluoride) 7 parts (exchange capacity when hydrolyzed: 0.91 milliequivalents/g dry membrane (Japan type)) and 3 parts of fine powder of Pb(NQ)2 and feed b(OH)2 with an average particle size of 2 microns or less (exchange volume 2.3 milliquivalents/night), and this was mixed in a beretizer. The mixture was poured into a container to homogenize the melt and form a pellet.

In order to further refine it, it was cooled with liquid nitrogen and crushed. Particles with a particle size between 20 mesh and 60 mesh are taken out and further mixed with 10% caustic soda meta/-
The mixture was soaked in a solution of 60 qo for 8 hours to obtain granular zwitterionic crosshair resin.

The exchange capacity of this resin was measured using a conventional method for intestinal ion exchange capacity and anion exchange capacity, and the cation exchange capacity was 0.62 milliequivalents/gram dry resin (Japan type), and the anion exchange capacity was 0. .69 meq. dry resin (OH type). Example 4 Exchange capacity when hydrolyzed with a copolymer of tetrafluoroethylene and perfluoro(3,6-dioxa-4-methyl-7-octensulfonyl fluoride) is 0.8
Uniformly distribute zirconium phosphate fine powder 4 with an exchange capacity of 2.0 meq/g of sulfonyl fluoride type polymer 6 base and average particle size each corresponding to 3 meq/g dry resin. The mixture was heated and melted to form a polymer film.

This was immersed in a 10% caustic soda methanol solution at 60° C. for 5 hours to hydrolyze the sulfonyl fluoride groups inside the membrane to obtain an intestinal ion exchange membrane. Table 1 shows the electrical resistance and transference number of the obtained film. When molding into a membrane, the same polytetrafluoroethylene cloth used in Example 1 was used as a reinforcing material in order to control the thickness of the membrane and increase the strength of the membrane.・Example 5 Exchange capacity when hydrolyzed with a copolymer of tetrafluoroethylene and perfluoro(3,6-dioxa-4-methyl-7-octensulfonyl fluoride) is 0.9
Copolymer 6 base part corresponding to 1 milliequivalent/g dry resin (Japan type) was mixed with 3 base parts of fine powder of titanium phosphate (average particle size: approx. 1
In order to further facilitate molding, one part of a copolymer of tetrafluoroethylene and propylene was mixed uniformly with a heated roll, and then a thick layer made of stainless steel was mixed. Place it in the mold on the 0.2 side 3
It was heated and pressurized to 20°C to form a sheet on the 0.2 side.

Furthermore, CF2=CF2 and CF2=CF○(CF2)3C
Exchange capacity when hydrolyzed with OF copolymer is 1.2
170 qo of 0.1 side sheet of polymer having ethylene fluoride groups corresponding to milliequivalent/gram dry resin
Pressure is applied at a pressure of 60k9/ground to fuse and integrate, 10
% KOH in methanol solution for 5 hours to perform hydrolysis. This resulted in an intestinal ion exchange membrane having one side of the membrane having carboxylic acid groups and the other side having sulfonic acid groups and phosphate groups of an inorganic ion exchanger. The electrical resistance of this film is 3.80, and the ring ratio is force * the surface with luponic acid groups is 2.
．． When facing saline, it is 0.89, and the surface containing the inorganic ion exchanger is 2. 0 when directed towards state saline.
It was 91. (Membrane) Separately, the same particle size exchange capacity as 70 parts of a copolymer of tetrafluoroethylene and propylene is 1
．． Three parts of titanium phosphate in an amount of 9 milliequivalents were uniformly mixed and melted with a heating roll to form a polymer sheet with a thickness of 0.2 mm in the same machine as above.

Then, on one side of this membrane, CF20=CF2 and F2=C
A copolymer of F○(CF2)3COF with the same exchange capacity as above and a thickness of 0.1 skin was fused and integrated at a pressure of 60 k9/ground at 17000, and the carboxylic acid fluoride was hydrolyzed with KOH to generate intestinal ions. It was used as an exchange membrane. The electrical resistance of this membrane was 18.80, and the transfer number was 0.86 when the carboxylic acid group was facing the concentrated saline side, but 0.73 when the inorganic ion exchanger side was facing the membrane. Ta. (Membrane Ro)
Using the ion exchange membranes 1 and 2 obtained above, electrolysis of saturated saline solution was carried out for each membrane.

Effective current carrying area 0. The main anode is made of titanium lath material coated with titanium oxide and ruthenium oxide.
Soft iron was used for the cathode. The current density was 2 M/d〆 and the electrolysis temperature was 90q0. The membrane was electrolyzed with the side with carboxylic acid groups facing the cathode. The results are shown in Table 2. Table 2 Example 6 Copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether sulfonyl fluoride having different exchange capacities when hydrolyzed as shown in Table 3 were tested for 5 anchorages and moldability. To facilitate this, mix 20 parts of a copolymer of tetrafluoroethylene and propylene, add 1.0 milliequivalent exchange capacity/3 parts of evening poppy, and 3 parts of acid zirconium with a particle size of 10 microns or less. In addition, the mixture was mixed uniformly and sandwiched between hot plates to form a sheet with a thickness on the 0.2 side.

This was soaked in a 10% NaOH methanol solution and hydrolyzed to obtain an intestinal ion exchange membrane. The electrical resistance and ring ratio of this were measured. The results are shown in Table 3. Table 3

Claims (1)

[Scope of Claims] 1. A non-crosslinkable fluorine-containing anionic polymer electrolyte with an exchange capacity of 0.3 meq/g dry polymer (H type) or more, or a derivative thereof, and an average particle size of 100 A method for producing an ion exchanger, characterized by uniformly mixing and melt-molding an inorganic ion exchanger of micron size or less. 2. The method according to claim 1, wherein the fluorine-containing anionic polymer electrolyte is water-insoluble. 3. The method according to claim 1, wherein the inorganic ion exchanger is cation exchangeable. 4. The method according to claim 1, wherein the inorganic ion exchanger is anion exchangeable.