DE2546911A1 - METHOD OF MANUFACTURING AN ION EXCHANGE MEMBRANE - Google Patents

Abstract

1485539 Ion exchange membranes MITSUBISHI PETROCHEMICAL CO Ltd 17 Oct 1975 [21 Oct 1974 25 Feb 1975] 42763/75 Headings C3B C3P and C3R Heterogeneous ion exchange membranes are prepared by mixing finely powdered ion exchange resin with a crystalline polyolefin resin, forming the resulting mixture into a membrane and treating the membrane at at least 80‹ C. with an aqueous solution of an alkali metal or ammonium salt of concentration at least 5 weight per cent. The polyolefin resin may be a polymer or copolymer of ethylene, propylene or butene. The ion exchange resin may be a sulphonated vinyl aromatic/divinyl benzene copolymer or phenol/formaldehyde condensate; or a reaction product of an epihalohydrin or polyglycidyl ether or ester with an amine, or a chloromethylated and aminated vinyl aromatic/ divinyl benzene copolymer or phenol/formaldehyde resin. The salt may be a chloride, bromide, iodide, sulphate, nitrate, phosphate, carbonate or acetate. Examples describe the preparation of membranes comprising polypropylene or polyethylene and sulphonated styrene/divinyl benzene copolymer, a hardened reaction product of epichlorohydrin/pentaethylene hexamine condensate and an epoxy resin, an epoxy resin/ amine reaction product or chloromethylated and aminated styrene/divinyl benzene copolymer, and treatment thereof with solutions of sodium chloride, carbonate, sulphate or acetate, potassium chloride or ammonium sulphate.

Description

Patent attorneys 0 0 Munich 2 2 Steinsdorfstrasse 21 - 22 Telephone 089/29 84 62

A 7576

MITSUBISHI PETROCHEMICAL Co. Ltd. 5-2, Marunouchi 2-chome, Chiyoda-ku, TOKYO / Japan

Method of manufacturing an ion exchange membrane

The invention relates to a method for producing an ion exchange membrane, in particular an improved method for producing a heterogeneous ion exchange membrane with a high ion transport number at a high concentration.

An ion exchange membrane, the special, has a to a · «carrier from synthetic fabric anchored Ionenaustauseher resin, has already been put to practical use · Such supported by synthetic fibers · Ionenaustauschaen bran is superior in mechanical strength of a homogeneous Ionenaustauechmembran consisting of a membrane au * Ion exchange resin itself exists, but the mechanical strength of the ion exchange membrane is not sufficient, so that its practical use suffers numerous restrictions . So it is, for example, to the applicability of the

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Ion exchange membrane by strengthening the chemical To improve the structure, it is necessary to increase the degree of cross-linking in the structure, thereby reducing the swellability of the membrane, which in turn lowers and increases the concentration of the ion-exchanging group leads to an increase in the resistivity of the membrane, although the ion transport number increases. The ion exchange membranes currently on the market swell when immersed in aqueous solutions and shrink when dried, causing the membranes to be deformed and broken and not put to practical use can be. Consequently, it is absolutely necessary to use membranes in a wet state and at room temperature, which hinders their practical use in an ion exchange device.

Since such an ion exchange membrane generally the In the absence of flexibility, there are some difficulties in using this ion exchange membrane in one Ion exchange device, and other possible uses of the ion exchange membrane, in which the ion exchange ability is exploited, are also excluded.

In order to produce a novel heterogeneous ion exchange membrane capable of overcoming the disadvantages described above, it has heretofore been proposed to mix a finely powdered ion exchange material with a polyolefin resin as a matrix, to mold the mixture and to subject it to a post-treatment with hot water, as in the published Japanese Patent application No. ₀ 24262/1972, 53189/1974 and disclosed in JA-PS 43038. The ion exchange membranes produced by this process can be used as ion exchange membranes for ent

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salts of an aqueous solution with a relatively low ion concentration are used in practice, however, are not satisfactory as an ion exchange membrane for desalination of an aqueous solution with a relatively high Concentration «That is, the heterogeneous ion exchange membrane produced by the method described above shows an appropriately low specific resistance, but at the same time has the disadvantage that the ion transport number is greatly reduced.

The invention is therefore intended to provide an improved method for making a heterogeneous ion exchange membrane; it should enable the production of a heterogeneous ion exchange membrane, i.e. a cation or anion exchange membrane with excellent electrochemical properties in an aqueous solution with a high ion concentration without deterioration in flexibility and mechanical strength of the membrane; and you is supposed to be a heterogeneous ion exchange membrane with a well balanced ion transport number and specific resistance value deliver.

The invention therefore relates to a method of the type mentioned at the beginning for the production of a heterogeneous ion exchange membrane with a high ion transport number at a high ion concentration, which is characterized in that a finely powdered ion exchange material mixed with a crystalline polyolefin resin, the mixture obtained into a membrane or a membrane-shaped body shaped and the membrane or the merabran-shaped body is treated with an aqueous solution of at least one alkali metal salt and / or ammonium salt with a concentration of 5 percent by weight or above at 80 ^° C. or above

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In the present invention, fundamental investigations have been made on a heterogeneous ion exchange membrane, particularly on the relationship of a synthetic resin as a matrix and an ion exchange resin as a leading part of ion exchange dialysis, and it has been found that the properties of a heterogeneous ion exchange membrane are greatly changed by post-treatment. Thereafter, various post treatments were examined in detail to improve the heterogeneous ion exchange membrane, whereby the present invention was made.

A heterogeneous ion exchange membrane produced by the conventional method contains an excessive amount of water at the boundary between a non-crystalline and hydrophilic ion exchange resin and a highly crystalline and hydrophobic synthetic resin matrix · The excessive amount of water in the membrane lowers the specific resistance of the Membrane, but on the other hand is presumably responsible for a strong reduction in the ion transport number at high ion concentrations. If further the water content in the If the membrane is lowered excessively, the resistivity of the membrane is increased too much for it to be practical would be usable. To have excellent properties Tjei one Therefore, in order to obtain high concentration, it is considered necessary to keep the water content in a heterogeneous ion exchange membrane to a minimum within the range so that the resistivity is kept well balanced.

Taking advantage of the fact that in an aqueous solution with a high ion concentration the water content an ion exchange resin and at the same time the degree of swelling is also reduced, has now been found that by mixing a finely powdered ion exchange resin

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zes with a crystalline polyolefin resin, forms the «obtained mixtures into a membrane and treating the membrane with an aqueous solution of at least one alkali metal salt and / or ammonium salt with a concentration of 5 % or above at at least 80 G of the water content in the heterogeneous ion exchange membrane, d, H. the content of the water contained in the ion exchange resin and in the intermediate layer between the ion exchange resin and the synthetic resin matrix in the aftertreatment stage can be controlled within the necessary minimum range. The present invention is based on this.

In the case of the heterogeneous ion exchange membrane produced according to the invention, the disadvantage of a heterogeneous ion exchange membrane produced by the conventional method, namely that the ion transport number is high Ion concentration is lowered, practically completely overcome, and the specific resistance of the membrane can be kept sufficiently low without the The flexibility and mechanical strength of the membrane deteriorate. Therefore, according to the invention Method produced heterogeneous ion exchange membrane satisfactorily for desalting an aqueous solution having a salt concentration so high that desalting using the heterogeneous ion exchange membrane was considered impossible according to the state of the art.

The invention is illustrated and explained in detail below with regard to the materials used:

(I) Polyolefin resins used as a matrix

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Crystallines containing predominantly olefin components Resins are used, e.g. olefin homopolymer, such as polyethylene and polypropylene, olefin-containing copolymers such as ethylene / propylene copolymer and ethylene / vinyl acetate copolymers and their mixtures

(II) ion exchange resins A. Fine powder cation exchange resins

1. An aromatic compound having a vinyl groupj which is able to easily take up a cation exchange group and a compound with 2 or more unsaturated, thus polymerizable bonds in the molecule are subjected to suspension copolymerization in an aqueous medium, and the result is bead-shaped copolymer is with an ijulfonierung - medium treated, which is then finely powdered mechanically.

2. An aromatic compound containing vinyl groups, the a cation exchange group can easily take up, and a compound with 2 or more unsaturated, thus polymerizable bonds in the molecule are in an aqueous medium of the emulsion copolymerization subjected, and the resulting fine powdery copolymer is treated with a sulfonating agent

3. A cation exchange resin, which essentially consists of a cocondensate of a phenol compound and formaldehyde, is mechanically finely powdered.

Examples of aromatic compounds which can be used in the present invention Compounds with vinyl groups and the ability to

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receiving a light Kationenaustausohgruppe are styrene, vinyltoluene, ethylvinylbenzene _t »^ -Methyletyrol, vinylnaphthalene and derivatives thereof. These compounds can be used individually or in combination.

As a compound with two or more polymerizable unsaturated bonds in the molecule, divinylbenzene is generally used.

B. Fine powder anion exchange resins

1. Become an epoxy compound and an amine compound reacted and cured, and the cured epoxy-amine condensate obtained is mechanically finely powdered.

Examples of the epoxy compound used here are the following:

a) Epihalohydrin compounds
Epichlorohydrin, of-methylepichlorohydrin, etc.

b) Compounds with two or more glycidyl ether groups in the molecule

Bisphenol A type epoxy compounds »the following formula

CH, I ·?

0 - (/ ^ -c --- f ^ - 0-CH ₂ -CH-CH ₂ "

CH ₅ -CH-CH

0 CH

CH,

0 - (/ yC- ^ Λ-0-CH ₃ -CH-CH.

CH ^{Χζΐ /} \ / ^CH 3 0

and epoxy compounds of the novolak type of the following

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the formula CH.

CH.

CH.

CHr

wherein R is hydrogen or an alkyl group, such as. B. a methyl group means.

c) Compounds with two or more glycidyl ether groups in the molecule

Compounds, such as those represented by the following formula:

COOCH _n -CH-CH ² \ /

COOCH ₃ -CH-CH.

d) Compounds with glycidylamino groups of the following general formula

CH ₂ CHCH

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in which R denotes an alkyl group.

e) compounds with two or more cirane rings

Compounds, such as those represented by the following formulas: 0

The amine compound used here is, for example, ine Compound of the general formula NH, in which R is a hydrogen atom, an alkyl group or the group

CH-CH.NH> - H <£ Λ η

is.

2. An aromatic compound with vinyl groups and represents Ability to easily accept an anion exchange group and a compound with two or more unsaturated, so that polymerizable bonds in the molecule are subjected to the suspension copolymerization in an aqueous medium, and the bead-shaped copolymer obtained! - sat is then subjected to chloromethylation and amination, after which it is mechanically finely powdered

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Examples of the aromatic compound having vinyl groups and the ability to easily absorb one Anion exchange group used according to the invention are styrene, vinyltoluene, ethylvinylbenzene, c / '- methyl styrene, vinyl naphthalene and their derivatives. These compounds can be used individually or in combination.

As a compound with two or more polymerizable Unsaturated bonds in the molecule divinylbenzene is usually used.

An anion exchange resin that consists essentially of consists of a condensate of a phenolic compound and formaldehyde, it is mechanically finely powdered

The mixing ratio of a polyolefin resin (X) and a finely powdered cation or anion exchange resin (II) is usually 2: 8 to 8: 2 based on the weight, preferably from 6 to 7: 3. When the mixing ratio of a polyolefin resin (I) is smaller than this range (20% by weight), the mechanical strength of the formed ion exchange membrane decreases and cannot be put to practical use, while if it exceeds this range (80% by weight), the specific resistance of the formed ion exchange membrane increases to an undesirable extent these components can be determined depending on the intended use

Mixing a polyolefin resin (I) and one fine powdered cation or anion exchange resin (II) can be used after each to uniformly mix the two

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Components are carried out using suitable processes, e.g. with the aid of an extruder or rollers. Mixing is preferably carried out at a temperature above the melting point of the polyolefin resin. Other additives such as antioxidants, colorants, fillers, lubricants, etc. can be used be added at this mixing stage or at another stage.

The mixture obtained in this way then becomes, for example, a film of 0.1 to 3 mm, generally 0.2 up to 1 mm, or formed into a sheet under suitable conditions using rollers, extruders or presses. The mixing stage described above can be used as a substitute for the softening stage, which must be carried out before molding.

The membrane-shaped article produced in this way is then subjected to an aftertreatment, as described below, in order to achieve the properties of an ion exchange membrane. The aftertreatment is carried out in such a way that this membrane-like article is immersed in an aqueous solution of an alkali metal salt or ammonium salts having a predetermined concentration at 80 ⁰ C for a suitable period. If metal salts other than these salts are used, the other metals, especially transition metals, combine with the ion exchange resins to form chelate compounds and are consequently difficult to remove by dissociation.

Usable examples of the alkali metal salt are alkali metal halides such as lithium, sodium, potassium, Rubidium, Caesiura chloride, lithium, sodium, potassium, rubidium, cesium bromide, lithium, sodium, potassium, Rubidium and cesium iodide, alkali metal sulfate, such as

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IJ. Lithium, sodium, potassium, rubidium and cesium sulfate, alkali metal nitrates, such as lithium, sodium, Potassium, rubidium and cesium nitrate, alkali metal phosphates such as lithium, sodium, potassium, rubidium, cesium phosphate, and alkali metal acetates such as e.g. lithium, sodium, potassium, rubidium and cesium acetate.

Usable examples of the ammonium salt are aramonium hydroxide, ammonium chloride, ammonium sulfate, ammonium nitrate, Ammonium phosphate and ammonium acetate.

The concentration of the alkali metal or ammonium salt is usually 5 percent by weight to saturation, preferably 10 percent by weight to saturation. The transport number increases with increasing salt concentration, but the specific resistance tends to increase. Therefore, depending on the intended use, a suitable concentration should be selected within a range of 5% by weight or more, since if less than 5 %, the ion transport number becomes too small «

The time required for immersing the membrane-shaped object is generally 10 minutes or more, preferably 20 minutes up to several hours.

The heterogeneous ion exchange membranes produced and post-treated in this way, i.e. cation and anion exchange membranes, develop excellent electrochemical properties * especially, they exhibit a good balance of ion transport number and resistivity high ion concentration of aqueous solution without deterioration in flexibility and mechanical strength of the

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Membrane.

Further advantages, features and embodiments of the invention emerge from the following more detailed description of the invention by means of the examples and comparative experiments. It is obvious to the person skilled in the art that the proportions, constituents of the formulations and the sequence of the measures can be modified within the scope of the invention. The invention is therefore not restricted to the individual examples. All parts, percentages and the like are by weight unless, otherwise indicated.

example 1

8 parts of divinylbenzene were added to 92 parts of styrene monomer, suspension copolymerized using benzoyl peroxide as a catalyst and copolymer granules being obtained, and then sulfonated with oleum to give a strongly acidic cation exchange resin (A) (ion exchange capacity = 4.5 meq / g). The resin (A) was treated with a vibration mill to a particle size of O _t O44 mm or less (325 mesh Tyler or more) of finely pulverized. 40 parts of polypropylene were added to 60 parts of this fine cation exchange resin powder, mixed in a roller mill and pressed to form a membrane (B).

The membrane-like product obtained was immersed in an aqueous, saturated sodium chloride solution at 100 ^° C. for 30 min to form a heterogeneous cation exchange membrane with a thickness of 0.7 mm, an ion transport number of 0.92 and a specific resistance of 115 Ω. . cm.

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Comparative example 1

The membrane-shaped obtained in an analogous manner in Example 1 Product (D) was placed in hot water for 30 min 100 C immersed, so that a heterogeneous cation exchange membrane a thickness of 0.7 mm, an ion transport number of 0.80 and with a specific resistance of 8 * t «Ω. · Cm was obtained.

Example 2

The analogue in the example 1 thus obtained membrane-shaped product (B) was immersed into a saturated aqueous sodium chloride solution at 100 ⁰ C for one hour, mm is a heterogeneous cation exchange membrane having a thickness of 0.6, an ion transport number of
0.92 and a specific resistance of 125 ε * · · on.

Comparative example 2

The membrane-shaped body (B) obtained in an analogous manner in Example 1 was immersed in hot water at 100 ° C. for one hour to form a heterogeneous cation exchange membrane with a thickness of 0.7 mm, an ion transport number of 0.77 and a specific resistance of 85 SX . cm.

Example 3

The strongly acidic cation exchange resin (A), obtained analogously to Example 1, had a particle size of 0.1 mm or less (150 mesh or more) pulverized with a vibrating mill. 60 parts of the powdered cation exchange resin obtained

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Ze "were made with HO parts of polypropylene In a rolling mill" ςοιηlacht and formed into a film. Since · · · ο obtained inoHilirnnförini ge Krzeugnit was in a geaHttigte wKaa ri, i? E solution of sodium chloride at 100 C for 60 min oiiiRftfniiclit, mm a heterogeneous Kationenauatauaohmembran with "Iner thickness of 0.4, a Ionentranaportzahl of Ο, Π9 and a resistivity of 270 «Cl · o *.

Comparative example 3

Analogously to Example 3 membranous product obtained was immersed in hot water at 100 ⁰ C for one hour, a heterogeneous Kationenaustauschmerabran with a thickness of 0.4 mm, an ion transport number of 0.70 and a resistivity of 250 Λ · cn to obtain .

Examples 4 to 7 and Comparative Example 4

The membrane-shaped product obtained analogously to Example 1 They were immersed in saturated aqueous sodium chloride solutions at temperatures according to Table 1 for 30 minutes immersed. The strength, ion transport number and resistivity of these cation exchange membranes are compiled in table 1.

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- i6 -

Tabel

Example 4_

Treatment ^{temperature (0} C)

Strength (mra) 0.75

Ion transport number 0.93

specific resistance (jQ.cm)

Compare · example

90 95 100 105 70 0.7 0.65 0.7 0.65 0.75

0.92 0.93 0.92 0.93 0.94

230 196 115 130

300

Examples 8 to 10 and Comparative Example 5

The obtained analogously to Example 1 nembranförmigen products were immersed in aqueous solutions with concentrations shown in Table 2 at 100 ⁰ C for 30 minutes. The strength, ion transport number and the specific resistance of the heterogeneous cation exchange membranes obtained are summarized in Table 2

Tabel example

Concentration of the aqueous sodium chloride solution (percent by weight )

Thickness (mm)

0.7

10

0.65 0.7

Comparing) ·! · Game

J- 1

17 29 2

(saturated)

0.7

0.7

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Continuation of table 2

Comparative example Example 8 9 10 1 5

Ion transport 0.84 0.86 0.92 0.92 0.8l

more specific

Resistance 108 119 125 115 90 (ST!. Cm)

Examples 11 to 15 and Comparative Examples 6 and 7

The membrane-shaped products obtained analogously to Example 1 were immersed in 23% strength aqueous solutions of alkali metal compounds, as shown in Table 3, at 100 ° C. for 30 minutes. The strength, ion transport number and the specific resistance of the heterogeneous cation exchange membranes obtained are shown in Table 3.

Table 3 strength
(mm) Ion transport
number more specific
resistance
(Ώ cm) example Alkali metal
link 0.7 0.89 99 11 sodium 0.7 0.88 123 12th Sodium sulfate 0.7 0.88 115 13th Sodium acetate 0.7 0.89 110 Ik Potassium chloride 0.7 0.90 118 15th Ammonium sulfate 0.7 0.95 400 Comp. - ₆
ex. Copper sulfate 0.7 0.93 550 Comp.-
ex. Calcium chloride

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example l6

92 parts of monomeric styrene were mixed with 8 parts of divinylbenzene mixed, using potassium perulfate as a catalyst emulsion copolymerized to form a fine copolymerized powder to obtain, and then sulfonated with oleum, creating a finely powdered, strongly acidic cation exchange resin with an ion exchange capacity. from 5 »2 meq / g

60 parts of the finely powdered cation exchange resin obtained were mixed with kO parts of polypropylene in a rolling mill and compression molded to give a membrane article. The membrane-shaped article was immersed in a saturated aqueous sodium chloride solution at 1OO C for 30 minutes so as mm heterogeneous KationenauatauBchmembran with a thickness of 0.70 to obtain a Xonentranaportzahl of 0.89 and a resistivity of IO3 SX · on.

Example I7

90 parts of monomeric styrene were mixed with 10 parts of divinylbenzene mixed, emulsion copolymerized using potassium persulfate as a catalyst to form a fine powdery copolymer to obtain, and then sulfonated with oleum, with a finely powdered, strongly acidic cation exchange resin with an ion exchange capacity of 4.9 meq / g.

60 parts of the powdery cation exchange resin were mixed with 40 parts of polypropylene in a rolling mill and press-formed into a membrane-shaped product membrane-shaped product was immersed in a saturated aqueous sodium chloride solution at 100 ° C for 30 minutes, around a heterogeneous cation exchange membrane with a thickness

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of 0.1 mm, an ion transport number of 0.89 and one
to obtain a specific resistance of 112 Λ · cm.

Example l8

71 parts of epichlorohydrin were reacted with 100 parts of pentaethylene hexamine, the resulting starting reaction product
57 parts of Epicoat 828 (WPE = 180) were added and
the mixture is adequately mixed and hardened, whereby
a moderately basic anion exchange resin (C) is obtained
(ion exchange capacity = 8.3 meq / g).

The anion exchange resin (C) was made to have a grain size of 0.044 mm or below (325 mesh or more) by means of a
Finely pulverized vibratory mill. 60 parts of the finely pulverized anion exchange resin were mixed with 40 parts of polypropylene by means of a roll mill and press-molded into a membrane-shaped product (D).

The membrane-shaped product thus obtained was immersed in a saturated aqueous sodium chloride solution at 100 ° C. for 30 minutes
immersed for a long time to form a heterogeneous anion exchange membrane with a thickness of 0.85 "im, an ion transport number of 0.91 and a resistivity of 125 Ώ · cm
to obtain.

Comparative example 8

The membrane-shaped product (D) obtained analogously to Example i8 was immersed at 100 C for 30 minutes to form a heterogeneous anion exchange membrane with a thickness of 0.90 mm, a Ion transport number of 0.85 and a specific resistance of 90 Ώ. "Cm.

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Obtained from Example 1 above, moderate amount of anion anate noncher resin (C) was bob to a grain size of 0.044 o <l «r underneath (32? me eh or more) finely pulverized. 50 parts of the finely powdered Aniontauatauicherharz ·· were mixed with 50 parts of polypropylene by means of rollers and compression-molded to form a membrane-shaped product (E).

The obtained membrane-shaped product (E) was in a saturated aqueous sodium chloride solution at 100 ° C. for 30 min long immersed to a heterogeneous anion exchange membrane with a thickness of 0.70 mm, an ion transport number of 0.93 and a specific resistance of 160 «Ω. Cm to obtain.

Comparative example 9

The membrane-shaped product (E) obtained analogously to Example 19 was immersed in hot water at 100 ° C. for 30 minutes, an anion exchange membrane having a thickness of 0.7 μm, an ion transport number of 0.86 and a specific resistance of 140 -Cl · cm was obtained.

Example 20

An epoxy-amine anion exchange resin (Duolite A-57; ion exchange capacity = 7 ~ 8 meq / g) was finely pulverized to a grain size of 0.044 mm or below (325 mesh or more) by means of a vibrating mill. 60 parts of the finely powdered anion exchange resin a were mixed with kO parts of polypropylene by means of a roller mill and pressure-molded to give a membrane-shaped product (F).

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The membrane-shaped product (P) obtained trurde immersed minutes in a · saturated aqueous Natriumchloridlöeung at 100 C for 30 to a heterogeneous anion exchange membrane having a thickness of O _t 65 mm, a Ionentran · - port number of 0.92 and a resistivity of 2 ~ 0 -Ω cm.

Comparative example 10

The membrane-shaped product (F) obtained analogously to Example 20 was immersed in hot water at 100 ° C. for 30 minutes, a heterogeneous anion exchange membrane with a thickness of 0.70 mm, an ion transport number of 0.87 and a specific resistance of 170 O. · Cm was obtained.

Example 21

92 parts of monomeric styrene were mixed with 8 parts of divinylbenzene using benzoyl peroxide as a catalyst suspension copolymerized to form a copolymer! to obtain, and then the chloromethylation with chloromethyl methyl ether and also the amination with trimethylamine subjected to a strongly basic anion exchange resin (6; ion exchange capacity = 1.3 meq / g) was received.

The resulting strongly basic anion exchange resin (G) (325 mesh or more) in a vibrating mill to a particle size of 0.044 mm or less finely divided · 60 parts of this finely powdered anion exchange resin were mixed with kO parts high-density polyethylene were kneaded in a roll mill and then a membrane-shaped product (H) molded under pressure.

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The obtained membrane-shaped product (H) was immersed in a saturated aqueous sodium chloride solution at 100 ° C. for 30 minutes to form a heterogeneous anion exchange membrane having a thickness of 0.70 mm, an ion transport number of 0.92 and a specific resistance of 125 -Ω . · Cm.

Comparative Example 11

The membrane-shaped product (H) obtained analogously to Example 21 was immersed in hot water at 100 ° C. for 30 minutes, whereby a heterogeneous anion exchange membrane with a thickness of 0.70 mm, an ion transport number of 0.85 and a specific resistance of 102 £ X cm was obtained

Example 22

The moderately basic anion exchange resin (C) obtained analogously to Example 18 was finely pulverized in a vibrating mill to a grain size of 0.044 mm or less (325 mesh or more). 60 parts of this finely powdered anion exchange resin were sufficiently mixed with kO parts of polypropylene by means of a roller mill and shaped into a film, which resulted in a membrane- shaped product (I).

The obtained membrane-shaped product (i) was immersed in a saturated sodium chloride aqueous solution at 100 ° C. for 30 minutes to obtain a heterogeneous anion exchange membrane having a thickness of 0.40 mm, an ion transport number of 0.94 and a specific resistance of 190 [mu] cm was th .

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Comparison chart 12

The membrane-shaped product obtained analogously to Example 22 (I) was immersed in hot water at 100 C for 30 minutes, being a heterogeneous anion exchange membrane with a thickness of 0.40 mm, an ion transport number of 0.84 and a specific resistance of 160 Ω · cm became -

Examples 23 to 27 and Comparative Example 13

The membrane-shaped products obtained analogously to Example 22 (I) Were in a saturated aqueous sodium chloride solution at various temperatures, as in Table 4 indicated, submerged. The membrane thickness, the ion transfer port number and the resistivity of the obtained heterogeneous anion exchange membranes are shown in Table 4.

Table 4 example

Treatment temperature (C)

Thickness (mm)

Ion transport number

more specific
resistance

(ß. cm)

80 o, 4 o

0.95 24o

24

90 o, 4 o

0.92

200

Comparative example

15th

100 105 70

o, 4o o, 4o o, 4o 0.94 0.93 0.90

190

180

280

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Moiaptele 26 bia 2 »and comparative chapter 14

The membrane-shaped products (I) obtained analogously to Example 22 were in aqueous sodium chloride solutions of various concentrations, as indicated in Table 5, ho i immersed for 100 C for 30 min. The strength, ion tears Port number and specific resistance of the heterogeneous anion exchange membranes obtained are given in Table 5.

Table 5 example

26 27 28

Comparison

Appendix 22 15

Concentration of the aqueous sodium chloride solution (% by weight )

Thickness (mm) 0.40 Ion transport

number

0.89

more specific Opposition 132 (Λ cm)

20 29 3 (saturated)

0.40 0.40

0.91 0.92

I60 175

0.40 o, 4o

0.94 0.82

190

105

Examples 29 to 33

The membrane-shaped products (I) obtained analogously to Example 22 were in 23 percent strength by weight aqueous solutions of Alkali metal compounds or ammonium compounds as shown in Table 6, immersed at 100 ° C for 30 minutes. the

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Strength, number of ions and the specific resistance of the heterogeneous anion exchange membranes obtained compiled in table 6.

Table 6

neiapiel £ 2 IS !. H i £ 12.

Alkali metal, sodium, sodium, sodium, potassium, aramonium and ammonium carbonate sulfate acetate chloride sulfate links

Thickness (mm) 0.40 0.40 0.40 0.40 0.40

Ion transport

number 0.94 0.91 0.91 0.91 0.93

more specific

Resistance 359 258 192 175

( Ω. Cm )

The ion exchange capacity, ^ on transport number and the resistivity in the examples described above are measured as follows:

1) ion exchange capacity; In the case of a cation exchange resin, 1 g of a dry cation exchange resin or heterogeneous cation exchange membrane is treated with hydrochloric acid in order to convert the cation exchange groups completely into the form, subjected to an ion exchange reaction with an aqueous sodium chloride solution, and the amount of Na exchanged for H. was expressed in milliequivalents

2) Ion transport number: calculated by separating a 0.5 η aqueous sodium chloride solution and a 0.005 η aqueous sodium chloride solution through a membrane and measuring the membrane potential between the two aqueous solutions.

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Specific resistance; Electrical resistance ( & cm) of a membrane when an alternating current (frequency 1000 Hz) is passed into a 0.5 η aqueous sodium chloride solution.

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Claims (12)

PATENT CLAIMS 1. Process for the production of a heterogeneous ion exchange membrane with a high ion transport number high ion concentration, characterized in that a finely powdered ion exchange material is mixed with a crystalline polyolefin resin, the resultant gel formed into a membrane-shaped object and the ■ · ■ -brand-shaped object with an aqueous solution of at least one salt from the group of alkali metal salts and ammonium salts at a concentration of at least 5 percent by weight at a temperature of at least 80 ⁰ C is treated. 2. The method according to claim 1, characterized in that the polyolefin resin and the ion exchange resin in one Weight ratio in the range of 2: 8 to 8: 2 can be mixed. 3. The method according to claim 2, characterized in that the polyolefin resin and the ion exchange resin in one Weight ratio ranging from 4: 6 to 7: 3 mixed will. 4. The method according to any one of claims 1 to 3 t, characterized in that the crystalline polyolefin polyethylene, Polypropylene or polybutene is used. 5. The method according to any one of claims 1 to 3, characterized in that the crystalline polyolefin is ethylene or copolymers containing pylene are used _{A 7576} 6098 18/08 19 6. The method according to any one of claims 1 to 5 _f, characterized in that the alkali metals used are lithium, sodium, potassium, rubidium and cesium . 7. The method according to any one of claims 1 to 6, characterized in that that chloride, sulfate, nitrate, phosphate and acetate is or are used as salt (s). 8. The method according to any one of claims 1 to 7 _f, characterized in that the alkali metal salt (s) used is or are sodium chloride, sodium carbonate, sodium sulfate, sodium acetate and potassium chloride. 9. The method according to any one of claims 1 to 8, characterized in that the aqueous solution is used with a concentration of at least 10 percent by weight . 10. The method according to any one of claims 1 to 9 »characterized in that that the treatment is carried out for at least 10 minutes. 11. The method according to claim 10, characterized in that the treatment is carried out for 20 minutes to several hours will. 12. The method according to claim 1, characterized in that the polyolefin resin and the ion exchange resin are mixed in a weight ratio of 6 to 7 * 3 and the treatment with an aqueous solution of at least one salt from the group consisting of sodium chloride, sodium sulfate, potassium chloride, potassium sulfate, ammonium chloride, ammonium sulfate with a contact * concentration of at least 10% at a temperature of at least 80 ⁰ C for at least 10 min is performed. 609818/0819