JPS58151483A - Method of setting ion exchange film in electrolytic cell - Google Patents

Abstract

A method of installing an ion-exchange membrane in an electrolytic cell in which the membrane is expanded by stretching to increase the surface area per unit weight of the membrane and the expanded, stretched membrane is secured to the electrolytic cell or to a part thereof. The stretching is preferably effected at elevated temperature and the expansion produced by stretching may be <<locked>> into the membrane by cooling the expanded, stretched membrane to a lower temperature prior to installation of the membrane in the electrolytic cell.

Description

[Detailed Description of the Invention] A method of installing an ion exchange membrane produced by Reihatsu@sha in an electrolytic cell will be discussed.

Electrolytic cells of the type are known, which include a large number of anodes and cathodes, each of which is separated from an adjacent cathode by an ion exchange membrane that divides the electrolytic cell into a number of positive chambers and negative chambers. It is being The anode* of such an electrolytic cell is provided with a device for appropriately supplying an electrolytic solution from a common header to the electrolytic cell and a device for taking out electrolyzed products from the electrolytic cell. Similarly K.

The camellia chamber of the electrolytic cell is provided with a device for removing the electrolyzed product from the cell and optionally for supplying water or other liquids to the cell. The electrolytic cell may be monopolar or bipolar.

For example, a filter press electrolyzer may consist of as many as 9 anodes and cathodes in an alternating arrangement, e.g. 50 anodes and 950 anodes in an alternating arrangement, but even more. and cathodes, e.g. 150 arranged alternately
It can also consist of up to two anodes and a cathode.

In such electrolytic cells, the ion exchange membrane is essentially water impermeable (hydraulively impermeable).
In use, ionic species, e.g. hydrated ionic species, are transferred across the ion exchange membrane between the s, iut and the cathode chamber of the electrolytic cell. For example, when electrolyzing an aqueous alkali metal chloride solution in an electrolytic cell with a Kabuon exchange membrane, the aqueous solution is supplied to the anode chamber of the electrolytic cell, and the depleted (alkali metal An electrolytic cell capable of supplying water or a dilute alkali metal hydroxide aqueous solution by extracting an aqueous solution of addend chloride with a reduced chloride content from the anode chamber and passing the alkali metal ions across an ion exchange membrane. The hydrogen and the alkali metal hydroxide latent solution produced by the reaction between the alkali metal ions and hydroxide ions are taken out from the cathode chamber of the electrolytic cell.

The electrolytic cell of the above type uses electrolysis of IJium (chloride)]
0K41KI, which manufactures chlorine and sodium hydroxide! It can be worn.

In such electrolysis 11I, the ion exchange membrane is, for example!
fixed in the electrolytic cell] by tightening between the scuts.

The ion exchange membrane was under tension in the electrolytic cell (Botto Hariichi *
) (taut) condition, and it is desirable that the ion exchange membrane be in tension when the electrolyte is charged into the electrolytic cell and the turtle electrolytic cell is operated. However, if the ion-exchange membrane is attached to the electrolytic cell with dry cloth and fixed in the electrolytic cell under tension, the

When the electrolyte comes into contact with the ion exchange membrane in the electrolytic cell.

It has been observed that ion exchange membranes swell and expand, resulting in a flaccid appearance and, in some cases, wrinkles.

As a result, the gas discharge is uneven and the voltage across the electrolytic cylinder increases. This is a particular disadvantage when the electrolytic cell is operated with a small anode-cathode spacing or with zero space.

To reduce the swelling problem when using this ion exchange membrane, for example, the ion exchange membrane is immersed in water, sodium chloride, lithium aqueous solution or sodium hydroxide aqueous solution before installing the ion exchange membrane in the electrolytic cell. Therefore, it has been proposed to preswell. Ideally, ion exchange 1
a. The dry ion exchange membrane should be preswollen to the same extent as the swelling caused by contact with the electrolyte in the electrolytic cell. No. 4,000.057 of US Pat. That is, the ion exchange membrane is mixed with the medium for at least 4 hours after
Consists of contact with a liquid medium exhibiting a substantially flat expansion for one hour. Suitable liquid media include, for example, aqueous solutions of ethylene glyfur, glycerin, and higher Group II alcohols.

In the above method, all the ions are exchanged in an electrolytic cell with an electric moat and 11
OK to solve the problem of swelling of ion exchange membrane when ringed
Although useful, it has substantial drawbacks. That is, the preswollen ion exchange membrane is wet and remains wet even when installed in an electrolytic cell, and is therefore difficult to handle.

For example, if the ion exchange membrane has been preswollen by contact with a corrosive liquid, such as caustic/kill liquid, special care must be taken in handling. i large, II
It is difficult to fix a moistened ion exchange membrane in an electrolytic cell so that no leakage occurs between the membranes.

The present invention is a method of installing an ion exchange membrane in an electrolytic cell, and is a method K11l that does not have the drawbacks mentioned above.

According to the invention, therefore, before applying an ion exchange membrane made of an organic polymer containing an ion exchange group or a derivative that can be converted into an ion exchange group to an electrolytic cell, the ion exchange membrane is expanded; In a method for attaching an ion exchange membrane to an electrolytic cell, the ion exchange membrane is expanded by stretching, and the surface area per unit weight of the ion exchange membrane is Provided is a method for attaching an ion exchange membrane to an electrolytic cell, characterized in that the ion exchange membrane is increased.

In the method of the invention, an ion exchange membrane in the form of a sheet or film is expanded by stretching.

As a result, the surface area per unit weight of the ion exchange membrane is increased.

This expansion of the ion exchange membrane causes it to swell.

As a result, it is not based on the use of an expanding liquid. In fact, expansion by stretching is usually achieved by drying ion-exchanged lIK
It is preferable to perform the process on a dry ion exchange membrane, thus eliminating the substantial disadvantages that occur when using a liquid medium. Furthermore, expansion is not achieved simply by pressurizing the ion exchange membrane at elevated pressures and temperatures.

Stretching of the ion exchange membrane should be done with care to avoid tearing the membrane.

As in this **0 method, the stretching of the ion exchange membrane -
The use of elevated temperatures is very effective in preventing ion exchange IIO stress.

In the mode of operation of the present invention, when the ion exchange membrane is attached to the electrolytic cell, the ion exchange membrane is heated at once to rise, and the shell membrane is stretched at an elevated temperature, and the membrane is expanded and formed. A method of attaching an ion exchange membrane to an electrolytic cell is provided that avoids fixing the ion exchange membrane to the electrolytic cell or a portion of the cell.

The ion exchange membrane is then stretched at an elevated temperature, the membrane is stretched and held in an expanded state and cooled to a lower temperature, e.g. It is preferable to fix it to a part of it.

Stretching can be carried out, for example, by passing the ion exchange membrane around and through rollers operating at different circumferential speeds, and the expanded and stretched ion exchange membrane is then cooled to a lower temperature. can be annealed. Alternatively, ion exchange can be performed by applying stretching forces to opposite ends thereof, and the expanded and stretched ion exchange membrane can be annealed before cooling to a lower temperature. It can be carried out in an ion exchange membrane stretching frame or stretching device.

Ion exchange stretching can be carried out uniaxially or biaxially. Two-wheel stretching can be performed in two directions, simultaneously or sequentially.

When stretching an ion exchange membrane uniaxially, strips of relatively stiff material are attached to opposite ends of the ion exchange membrane so that the ion exchange membrane contracts in a direction perpendicular to the direction in which the iron membrane is stretched. and can be prevented.

If the ion exchange membrane is stretched, for example at an elevated temperature, then the ion exchange membrane, while in the expanded and stretched state, is subsequently cooled at a lower temperature, for example at or near ambient temperature. In this case, at least a part of the expansion caused by stretching is trapped within the membrane.
k'''). If the expanded and stretched ion-exchange membrane is mounted and fixed in an electrolytic cell and the ion-exchange membrane is brought into contact with an electrolyte at an elevated temperature of 41, for example 95@C in a chlor-alkali electrolytic cell. When brought into contact with 5ill of alkali metal chloride water at a high temperature of Although the ion exchange membrane is suppressed in the cell, the ion exchange membrane tends to shrink back to its original state. This tendency to shrink is due to the expansion of the membrane caused by the swelling caused by contact between the pus and the electrolyte.
As a result, the ion exchange membrane installed in the electric wire W8 remains in a taut state 111) and does not wrinkle during use.

The degree of expansion caused by stretching is approximately equal to or greater than the degree of swelling that occurs when the membrane comes into contact with the electrolyte in the electrolytic cell, so that the ion exchange membrane Preferably, it remains taut when in contact with the electrolyte. However, certain advantages may still be obtained if the amount of expansion caused by stretching is somewhat less than the amount of expansion caused by swelling of the ion exchange membrane upon contact with the electrolyte. The appropriate amount of expansion caused by stretching can be determined by simple testing. Generally, expansion of the ion exchange membrane caused by stretching increases the surface area of the membrane by at least 2-1, preferably It should be increased by at least 5 months. The large expansion of the membrane reduces the surface area of the membrane by at least 50% by stretching, for example.
Alternatively, it may be increased by at least 100 times, or optionally by a factor of 10 or more. Additional benefits are obtained when a substantial amount of stretching is performed.

That is, when a large expansion of the membrane is performed by stretching, when used in an electrolytic cell, the operating voltage is reduced, resulting in savings in power costs. Moreover, electroscale products can be produced in higher current motors.

In order to confine most of the expansion of the ion exchange membrane caused by stretching into the membrane, the ion exchange membrane is heated at a temperature lower than the 11° temperature increase at which it was expanded, stretched and held in a round state. can be reduced to However, if such an ion exchange membrane is used in an electrolytic cell, the shrinkage of the ion exchange membrane that occurs when the ion exchange membrane is brought into contact with the electrolyte at an elevated temperature is due to the The expansion caused by the swelling of the ion exchange membrane due to contact is 011 degrees) large), and the result! & The ion exchange membrane may tear. Whether or not the ion-exchange membrane has a tendency to tear depends, of course, on the degree of expansion of the resulting ion-exchange membrane (by stretching).

If the degree of expansion of the ion-exchange membrane caused by stretching is large, the ion-exchange membrane has a large surface area (e.g., per unit weight) and can therefore be operated at a substantially reduced voltage in the electrolytic cell. In order to obtain an
neal ) It is then preferably cooled to a lower temperature. In this method, sufficient expansion is trapped in the cell at one time to keep the ion exchange membrane taut and wrinkle-free when used in the cell. This can prevent the ion exchange membrane from tearing during use.

Ion exchange mu that is expanded by stretching can usually be in the form of wrinkles and can have a thickness of, for example, 0.2 to 2 cm.

Although extremely thin films can be produced using the method of the present invention,
Expanded and stretched ion exchange membranes must not be significantly damaged when used in an electrolytic cell because they are extremely thin. Expanded/stretched ion exchange membranes typically have at least 0.
02■, preferably at least 0.1■ The degree of stretching (raising) of the ion exchange membrane will vary depending on the type of ion exchange membrane. However, this temperature will usually be above 40'C, preferably above 55°C. Regarding specific ion exchange membranes,
The appropriate hot water temperature to be used can be selected by simple testing; this temperature should not be so high as to melt or otherwise significantly degrade the organic polymer of the ion exchange membrane.
The temperature at which the stretching is carried out will normally not exceed about 150@C.

When an expanded and stretched ion exchange membrane is annealed, the annealing temperature can be the same as or close to the temperature at which the membrane is stretched. The annealing temperature can be higher than the temperature at which stretching is performed. The time for annealing an expanded/stretched ion exchange membrane determines the degree of llolllllOIll that will be "trapped" in the membrane when the membrane is subsequently cooled to a lower #Asi*.
The longer this time, the less chance of annealing remaining 'trapped' during long s, m. Annealing times are typically at least 1 minute, but may be longer than 5 hours. It probably won't be catfish.

Ion exchange - cool it down to a low temperature.

ζO-mu, restraining force (r@straining for
ce ) is present at which the ion exchange membrane does not relax rapidly when removed from the membrane.

Cooling to or near ambient temperature is most convenient.

In another preferred embodiment of the invention, which is particularly useful in expanding ion exchange membranes to substantial root bark by stretching, the ion exchange membrane is stretched at elevated temperatures, and then the membrane is expanded and stretched. The process of cooling to a low temperature, for example, close to ambient temperature, and expanding by stretching at an elevated temperature, and the cooling process are each repeated at least once more while maintaining the same state. I will do it. In this method, stretching is performed in multiple steps to create the desired amount of expansion in the ion exchange 11, and the likelihood that the membrane will be damaged by tearing during stretching is reduced.

Preferably, the ion exchange membrane is a cation exchange membrane containing acidic groups or derivatives thereof that can be converted into acidic groups.

In order to withstand the corrosive atmospheres encountered in many electrolytic cells, particularly chlor-alkali electrolytic cells, ion exchange membranes are made of fluoro-11 compounds containing acidic groups or derivatives thereof, such as those mentioned above. Preferably, it is a ll1K''-fluoropolymer.

Suitable acidic groups include sulfonic acid, carboxylic acid, and phosphonic acid groups. Ion exchange membranes may contain up to two or more different acid groups. Suitable derivatives of acidic groups include salts of the above-mentioned groups, such as 1% metal salts and alkali metal salts.In particular, suitable derivatives include:
Derivatives that can be converted into acidic 1JIK by hydrolysis, such as acid-ride groups, such as -@0. ? and COF:
2)! Jru group -α; acid amide group -CQMn2 (R is hydrogen or alkyl group); acid ester group 1, such as -cooa (R is aldPjhl group).

Suitable AT cation exchange membranes are described in British Patent No. 1, ll4, for example.
J2+, 1.402,920. 1.406.6'
F3. 1,455. -0fu0. 14, 411
．． 1.49, 741, 1.518,387 and 1.531.06s.

It is preferable to use ion exchange membranes containing derivatives of acidic groups, since ion exchange membranes containing such groups are generally easier to stretch. For example, when the ion exchange membrane is a fluoropolymer containing carginic acid groups as ion exchange groups, it is preferable to stretch the ion exchange membrane in which the carboxyl groups are of the ester type 1, for example, methyl ester.

If the ion exchanger II! contains a group that is converted to an ion exchange group by hydrolysis, then the hydrolysis is performed by the ion exchanger II! The sample may be contacted with an aqueous alkali metal hydroxide solution, such as an aqueous sodium hydroxide solution. Ion exchange membranes tend to swell during hydrolysis, so
Such hydrolysis is carried out by fixing the expanded and stretched ion exchange membrane to the electrolytic cell or a part thereof.

It is preferable to carry out the following steps.

Ion exchange membranes may be reinforced with, for example, fluoropolymer nets, but such reinforcing nets are difficult to stretch and are therefore not preferred. The ion exchange membrane can be in the form of a laminate or coated with an electrostatic or non-electrode material.

The expanded/stretched ion exchange membrane is placed in an electrolytic cell or one 111K of the cell.
Iiii! do. If the membrane is expanded (by stretching) at an elevated temperature and becomes round, it can be fixed to the electrolytic cell or a part thereof while being maintained at an elevated temperature. However, since expanded and stretched ion exchange membranes are cooled to ambient temperature and therefore tend to condense during fixation, the membrane 0** should be In other words, the ion exchange membrane is stretched and expanded at an elevated temperature, cooled to a temperature of 1, preferably 1, and the iron membrane is stretched and expanded at a temperature of 1k. It is preferable to maintain the film at a state of 11 degrees so that the membrane removes the constraining force at 11 degrees and retains most of the expanded state.

The expanded/stretched ion exchange membrane is an electrolytic cell or a part of the electrolytic cell.
altFL Obtain 0 For example, in an ion exchange membrane electrolyzer, tighten firmly or loosely between a pair of scuts.

Alternatively, the ion exchange membrane can be fixed to the ion exchange 11a7 frame and then attached to the electrolysis 1, or the ion exchange membrane can be fixed on the electrode.

The method of the invention is particularly suitable for application to ion exchange membranes installed in electrolytic cells of the filter press type. A filter press type electrolytic cell may consist of a number of alternating anodes and cathodes and may have an ion exchanger provided between each anode and an adjacent cathode. Such an electrolytic cell may consist of, for example, 50 anodes and 50 cathodes arranged alternating therewith, but is more likely to consist of a large number of anodes and cathodes, fI
It may consist of up to 150 alternating anodes and cathodes.

In an electrolytic cell, the at-electrode can usually be made from metal or an alloy. The type of metal or alloy will vary depending on whether the electrode is used as an anode or a cathode, and also on the type of electrolyte to be electrolyzed in the cell.

When electrolyzing aqueous alkali metal hydroxide solutions and when the electrode is used as an anode, the electrode is suitably made from a film-forming metal or an alloy thereof, such as solfnium, dioxium, tungsten or tanker. However, it is preferably made from titanium and preferably has a coating of an electrically conductive electrocatalytically active material on the anode surface. This coating consists of platinum group metals,
That is, the oxides of platinum, ozone, iridium, ruthenium, 111 or more of palladium, and 111 or more of these metals can be formed. Coatings of platinum group metals and also fimonide are present in the form of oxides of one or more non-noble metals, in particular oxides of one or more film-forming metals, such as titanium dioxide. obtain.

Conductive electrically active materials for use as coatings on aSS in electrolytic cells for carrying out electrolysis of aqueous alkali metal chloride solutions and methods for coating such coatings are disclosed in Ij.
4@@ is well known.

When electrolyzing an aqueous alkali metal chloride solution and when the electrode is used as a cathode.

The electrodes are suitably manufactured from iron or steel or other suitable metals, such as tankard. It can be coated with a material that reduces the hydrogen overvoltage of cathodic electrolysis.

Any suitable construction of electrodes may be used in the electrolytic cell. For example, the electrode may be composed of a number of elongate members, such as rods or strips, or may have a perforated surface.
For example, it can be constructed from a perforated plate or extracted delta-noded metal.

A practical example of the present invention is shown below.

Practical Example 1 Tetrafluoroethylene containing carginic acid group)
From a 280 micron thick cation exchange membrane made of a copolymer with f-fluorovinyl ether and having an ion exchange capacity of 1.3 meq/l, 35 cl.
A rectangular sheet of lX3Q3 was cut out.

A strip of PvC elastic tape was attached to each of the 35 cn4 long sides of this sheet, and a strip of aluminum was attached to each of the 30 n long sides. This sheet was made by Zolluckner Kalo (Br-uekner Ka).
After loading into the drawing machine, the temperature of the sheet was raised to 670C in a heating furnace combined with the drawing.

Pull the PvC elastic strip at a rate of 1 m for 1 min until the distance between them increases by a factor of 3; This sheet was installed in the stretching machine in 91 minutes.
1. The mixture was taken out of the heating furnace and cooled to a temperature of 1 cm in a gust of air.

Repeating the above procedure twice, stretching the sheet at a temperature of 116 °C and cooling the sheet to ambient temperature,
In the first iterative step, the spacing of the aluminum struts was increased to 2.5 times the original spacing.

In repeat machining 1 of 1112m111, the aluminum strip O spacing was increased to 4.2 times the original spacing.

Take out the cation exchange membrane thus obtained from the stretching machine. The coating relaxed somewhat in the direction of the original dimensions of the sheet. The thickness of the coating after being slightly relaxed was get talon.

A pair of EPDM rubber gaskets were coated with the cation exchange membrane produced as described above!・A cathode consisting of a nickel mesh with a diameter of 7.53 and a mixture of % RuO2 and TiO□ (Ru
Diameter 7. with a coating consisting of O2 and Tie□ in a weight ratio of 35:65). ! The sample was placed in an electrolytic cell equipped with an anode made of 1111 titanium mesh.

−8, NaCl concentration 3 + N hcl of Ot/l
Charge the aqueous solution into the anode chamber of the electrolytic cell, charge water into the cathode chamber of the electrolytic cell, and heat NaC/ to 90°C in the electrolytic cell.
The NaC/2 concentration in the anode chamber was 200 f/l during the electrolysis operation.

A NaC/aqueous solution with reduced chlorine and NaC/ content was removed from the positive electrode, and a hydrogen and 'Na0)I aqueous solution (35 wt.) was removed from the cathode chamber.

Electrolysis was carried out at a current density of 1 d, l kA/m, and the electrolytic sliding voltage was 3.01 #rt.

After a total of 20 days of electrolysis, Tsuyoshi disassembled the electrolytic cell and
We investigated cation exchange membranes. It can be seen that the cation exchange membrane is under tension and has no wrinkles.

Rounding off the comparison, except that a 280 micron thick cation exchange membrane was used in the electrolytic cell, i.e. a sheet of cation exchange without stretching treatment.

Same as above 〇 Perform electrolysis operation 9.

The sliding voltage is 3.1 at a current density of I kA/gm ()
It was observed that the cation exchange membrane taken out from the electrolytic cell 61 at the root was wrinkled and not strained.

Example 2 Repeat the electrolysis procedure of Example I and Mall at a current density of 2 kl/we (). In this case, the sliding voltage is 324 #lt;
When taken out from the electrolytic cell, no wrinkles were observed.

Except for the fact that a sheet of cation exchange membrane with a thickness of 280 electrons was used in an electrolytic cell**, that is, without being subjected to stretching treatment.

Same as above 〇 Perform electrolytic operation -k.

The sliding voltage was 3.4 g when a current of 2 kA/a*' was applied at one time), and the cation exchange membrane taken out from the electrolytic cell was wrinkled and it was confirmed that it was not under tension.

II! Example 3 The same electrolytic operation as in Example 1 was repeated at a current density of 3 kk. In this case, the sliding voltage was 3.52 melt), and as in the case of Actual IIIA Example 1, when the ion exchange membrane was taken out from the electrolytic cell, it was observed that there was no tension or wrinkles. Ta.

For comparison, the same electrolytic operation as above was carried out, except that a 280 micron thick cation exchange membrane, ie, a sheet of cation exchange membrane that had not been stretched, was used in the electrolytic cell.

At a current density of 3 kVn, the sliding voltage was 3.7 volts], and the cation exchange membrane taken out from the electrolytic cell was found to be wrinkled and unstrained.

Example 4 A sample of a cation exchange membrane consisting of a copolymer with te) 9-fluoroethylenete/arm-fluorovinyl ether containing sulfonic acid groups in the form of potassium salt (I 1.5 cwx
A PVC tag was attached to the edge of the membrane (I 1.55+ ), and this ion exchange membrane was attached to a tenter frame. The ion exchange membrane was heated to a temperature of 180°C and 0.2°C.
With moderate stretching of 85 m/min, ion '1211111 is 2
．． The ion exchange membrane was uniaxially stretched until it was stretched 0 times, and then the ion exchange membrane was cooled to ambient temperature and removed from the tenter frame.

The same ion exchange with solid line Example I was carried out in the same electrolytic cell K11l as described in solid line Example I, and the same electrolytic operation as in solid line 1P112 was carried out; that is, the Nap/aqueous solution was 2 kAA'
Electrolyze at 0 current level. Concentration 25 weight - 08m01*l
ll11 was produced with a current efficiency of 50-. Hinoki Electric Power 2.
95 # It was Ruto.

When the electrolytic cell is disassembled, the ion exchange membrane becomes tense and jhj
L, L was not occurring.

The electrolytic operation was the same as above except that an ion exchanger without rounding or stretching was used. It was done.

When the electrolytic cell was disassembled, the ion exchange membrane was wrinkled and did not look tense.

m1RI5 ion exchange - 1 methyl ester group of carunic acid
have The same stretching operation as in Solid Line Example 4 was carried out, except that a copolymer of tetrafluoroethylene 5- and p+-fluorovinyl ether was used and the heating temperature when stretching the ion exchange membrane was 80'C. Ta.

This ion exchange membrane was deposited in the same electrolytic cell as described in the solid line example, and electrolysis was carried out by contact with a NaOH solution.The current efficiency of the NILOH NaOH solution with a concentration of 35 weight was obtained. was 3.32&&).

When the electrolytic cell is disassembled, the ion exchange membrane becomes tense and
It was observed that no wrinkles were formed.

For comparison, the same electrolytic operation as above was carried out except that an ion exchanger without stretching treatment was used. There are 3 electrolytic tanks
．． Operating at a voltage of 4 volts, a current efficiency as high as Na0HFi94 was obtained.

When the electrolytic cell was disassembled, the ion exchange membrane wrinkled and
It was recognized that the llI was not carried out.

Ikankai 6 Itsumugi Tsuba 5'e used 9th grade, Karin Shun Methyl Z x
Tetfluoroe containing f & 41? A sample of ion-exchanged copolymer of aluminum and vinyl ether was heated to a temperature of 67°C.

Stretch uniaxially on the ten-7 frame using the same method as the shield with Oku Sotsutsuba 4; however, in this example, the stretching mode is set to loi.
/min, (■) is a circle stretched to 4.3 times the original length, that is, to 430 mm of the original length in the stretching direction. After the stretching is completed, ion exchange is carried out in an air stream! It was rapidly cooled down to 11 degrees, and even 7 reams were removed.

After standing for 15 minutes, the membrane has shrunk by 5% KI in the stretching direction, so that in the ζ0 direction the membrane is 365 mm back to its original length.

IpH and Okasake electrolysis were carried out using the nine ion exchange membranes obtained above. After electrolysis was carried out for 20 days, it was observed that ion exchange 1 did not develop any tension or wrinkles.

Solid line examples 7 to 9 After completion of stretching, by heating at 679C for 1 minute (solid line example 7), 2 minutes (Oku Sokai 8) and 3 minutes (actual MIM 19) before cooling and removing from the tenter frame. ] Solid line N, except that three separate annealed samples were used.
Repeat the same method as 6.

15 minutes @K after taking it out of the tenter frame.

These ion exchanges occur in the direction of stretching, respectively.

+ 1fi (real #A example?), log (solid line example ε) and 9 width (1! pongee example 9) shrinkage was observed; that is, the ion exchange membrane was 383 times smaller than its original length in the stretching direction.
Width (actual example?), 3 Jl F% (solid example 8) and 391
9G (solid line example 9).

Using each of these ion exchange membranes! ! The same electrolytic operation as for Tsumugi 1 was performed. After 20 days of electrolysis, each S was found to be tense and wrinkle-free.

Claims (1)

[Claims] An ion exchange membrane made of an organic polymer containing a 1,4-one exchange group or a conductor that can be converted into an ion exchange group is installed at 11 K for electrolysis, and the ion exchange membrane is expanded. ,
When the expanded ion exchange membrane is fixed to the weight of the electrolytic cell or a part thereof, in the method of attaching the ion exchanger to the electrolytic cylinder, the ion exchange membrane is expanded by stretching, and its unit weight is A method for attaching an ion exchange membrane to an electrolytic @, characterized by increasing the *mr product of (a). 3. The method according to claim 1, wherein the ion exchanger is expanded by stretching at an elevated temperature. 3. Expand the ion exchange membrane by stretching at an elevated temperature;
The ion exchange membrane is held in an expanded and stretched state, cooled all at once, and then fixed to the cell or a portion thereof. Il! stated in claim 2! 015
Law. 4. The method according to any one of claims 1 to 3, wherein the ion exchange membrane is uniaxially stretched. 5. Stretch the ion exchange membrane biaxially. A method according to any one of claims 1 to 3. 6. The degree of expansion of the ion exchange membrane caused by stretching is the same as or greater than the degree of expansion of the membrane caused by contact between the membrane and the electrolyte, as claimed in claim 1. The method described in any of Items 1 to 5. 7. Stretching of the ion exchange membrane increases its surface area per unit weight by at least 5 points!
The method according to any one of Items III to 16. 8. By stretching the ion exchange membrane, its surface area (per unit weight) is increased by at least 100. The method according to claim 7. 9. A method according to any of claims 2 to 8, wherein the ion exchange sheet is stretched at a temperature of at least 558C. 10. Anneal the expanded/stretched ion exchange membrane by heating it at an elevated temperature. 121. The method according to any one of claims 2 to 9. 11. Stretching the ion exchange membrane at an elevated temperature (K) and then cooling the ion exchange membrane to a lower temperature by means of the tube in which the ion exchange membrane is expanded and stretched; A method according to any of claims #I1 to 1O, wherein the method is repeated at least -1 times. 13. Ion exchange - The method according to any one of claims 1 to 11, wherein the membrane comprises a fluoropolymer. 1B, the ion exchange group is a sulfonic acid group and (t) Calgin #! The method according to any one of claims 1 to 12, which is a group or a group that can be converted into these groups. 14@The method of claim 1I41113, wherein the ion exchange group is a carginic acid ester group.