阅读说明：本技术 层积体制造用夹具、层积体的制造方法、包装体、层积体、电解槽以及电解槽的制造方法 (Jig for manufacturing laminate, method for manufacturing laminate, package, laminate, electrolytic cell, and method for manufacturing electrolytic cell ) 是由 和田义史 立原博 松冈卫 船川明恭 角佳典 森川卓也 山本挙 于 2019-09-20 设计创作，主要内容包括：一种层积体制造用夹具,其用于制造电解用电极和隔膜的层积体,其中,该层积体制造用夹具具备：卷绕有长条状的电解用电极的电极用辊、以及卷绕有长条状的隔膜的隔膜用辊。(A jig for manufacturing a laminate for manufacturing an electrode for electrolysis and a separator, comprising: an electrode roll around which a long electrolysis electrode is wound, and a separator roll around which a long separator is wound.)

1. A jig for producing a laminate of an electrode for electrolysis and a separator,

it is provided with:

electrode roll around which a long electrolysis electrode is wound, and

a separator roll around which a long separator is wound.

2. The jig for manufacturing a laminate according to claim 1, further comprising:

and a water retention unit configured to supply water to at least one of the electrode roll, the separator roll, the electrolysis electrode wound out of the electrode roll, and the separator wound out of the separator roll.

3. The jig for manufacturing a laminate according to claim 2, wherein the water retention unit comprises an impregnation tank for impregnating the electrode roller and/or the separator roller.

4. The jig for manufacturing a laminated body according to claim 2 or 3, wherein the water retention unit includes a spray head.

5. The jig for producing a laminated body according to any one of claims 2 to 4, wherein the water retention unit includes a sponge roller containing water.

6. The jig for producing a laminate as set forth in any one of claims 1 to 5, further comprising:

and a positioning unit for fixing the relative positions of the electrode roller and the diaphragm roller.

7. The jig for manufacturing a laminated body according to claim 6, wherein the positioning unit presses the electrode roller and the separator roller against each other by a spring.

8. The jig for manufacturing a laminated body according to claim 6, wherein the positioning means fixes the positions of the electrode roller and the separator roller so that one of the electrode roller and the separator roller presses the other roller by its own weight.

9. The jig for manufacturing a laminate according to claim 6, wherein,

the electrode roller and the separator roller each have a rotation axis,

the positioning unit has a bearing portion of the rotating shaft.

10. The jig for producing a laminate as set forth in any one of claims 1 to 9, further comprising:

and a rolling roller for pressing at least one of the electrode for electrolysis and the separator, which are respectively wound out from the electrode roller and the separator roller.

11. The jig for producing a laminate as set forth in any one of claims 1 to 10, further comprising:

and guide rollers for guiding the electrode and the separator, which are respectively wound from the electrode roller and the separator roller.

12. A method for producing a laminate of an electrode for electrolysis and a separator, comprising the steps of:

a step of winding up the electrolysis electrode from an electrode roll around which the long electrolysis electrode is wound; and

and a step of winding the separator from a separator roll around which the long separator is wound.

13. The method for producing a laminate according to claim 12, wherein the electrolysis electrode and the separator roller are brought into contact with each other at a wrap angle of 0 ° to 270 ° and conveyed.

14. The method of manufacturing a laminate according to claim 12, wherein the separator and the electrode roll are brought into contact with each other at a wrap angle of 0 ° to 270 ° and conveyed.

15. The method of manufacturing a laminate according to claim 12,

in the step of winding out the electrode and/or the separator for electrolysis, the electrode and/or the separator for electrolysis is guided by a guide roll;

the electrolysis electrode is in contact with the guide roller at a wrap angle of 0-270 DEG and is conveyed.

16. The method of manufacturing a laminate according to claim 12,

in the step of winding out the electrode and/or the separator for electrolysis, the electrode and/or the separator for electrolysis is guided by a guide roll;

the diaphragm and the guide roller are contacted with each other at a wrap angle of 0-270 degrees for conveying.

17. The method for producing a laminate according to any one of claims 12 to 16, further comprising:

and a step of supplying water to the electrolysis electrode wound out from the electrode roll.

18. The method for producing a laminate as claimed in any one of claims 12 to 17, wherein the wound electrode for electrolysis and separator are respectively wound out with relative positions of the electrode roll and the separator roll fixed.

19. A package is provided with:

an electrode roll around which a long electrolysis electrode is wound and/or a separator roll around which a long separator is wound; and

and a housing for housing the electrode roller and/or the separator roller.

20. A laminate comprising:

an electrode for electrolysis; and

a separator laminated on a surface of the electrolysis electrode,

wherein the content of the first and second substances,

the separator has a concavo-convex structure on the surface thereof,

The ratio a of the volume of the gap between the electrolysis electrode and the separator to the unit area of the separator is greater than 0.8 [ mu ] m and not greater than 200 [ mu ] m.

21. The laminate according to claim 20, wherein a difference between a maximum value and a minimum value of the height in the textured structure, that is, a height difference, is greater than 2.5 μm.

22. The laminate of claim 20 or 21, wherein the standard deviation of the step difference in the textured structure is greater than 0.3 μm.

23. The laminate as claimed in any one of claims 20 to 22, wherein the interfacial water content w held at the interface between the separator and the electrolysis electrode is 30g/m²Above 200g/m²The following.

24. The laminate according to any one of claims 20 to 23,

the electrode for electrolysis has 1 or a plurality of undulation portions on the opposite surface facing the diaphragm,

the undulation portion satisfies the following conditions (i) to (iii),

0.04≦S_a/S_all≦0.55…(i)

0.010mm²≦S_ave≦10.0mm²…(ii)

1<(h+t)/t≦10…(iii)

in said (i), S_aRepresents the total area of the undulation part in an observation image obtained by observing the opposite surface with an optical microscope, S_allRepresenting the area of the facing surface in the observation image,

in said (ii), S_aveRepresents an average area of the undulations in the observed image,

In the above (iii), h represents the height of the undulation portion, and t represents the thickness of the electrolysis electrode.

25. The laminate of claim 24, wherein the undulations are each independently disposed in one direction D1 in the opposing plane.

26. The laminate as claimed in claim 24 or 25, wherein the undulations are arranged continuously in one direction D2 in the opposing plane.

27. The laminate according to any one of claims 24 to 26, wherein the mass per unit area of the electrode for electrolysis is 500mg/cm²The following.

28. An electrolytic cell comprising the laminate according to any one of claims 20 to 27.

29. A method for manufacturing a new electrolytic cell by disposing a laminate in an existing electrolytic cell including an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode,

the method comprises a step of exchanging the separator with the laminate in the existing electrolytic cell,

the laminate according to any one of claims 20 to 27.

30. A method for manufacturing a new electrolytic cell by disposing an electrode for electrolysis in an existing electrolytic cell including an anode, a cathode facing the anode, a separator disposed between the anode and the cathode, and an electrolytic cell frame including an anode frame supporting the anode and a cathode frame supporting the cathode, the anode, the cathode, and the separator being accommodated by integrating the anode frame and the cathode frame, the method comprising:

A step (A1) of releasing the integration of the anode frame and the cathode frame and exposing the separator;

a step (B1) of disposing the electrolysis electrode on at least one surface of the separator after the step (a 1); and

a step (C1) of, after the step (B1), integrating the anode frame and the cathode frame to house the anode, the cathode, the separator, and the electrolysis electrode in the electrolysis cell frame.

31. The method of manufacturing an electrolytic cell according to claim 30, wherein the electrolysis electrode and/or the separator are wetted with an aqueous solution before the step (B1).

32. The method of producing an electrolytic cell according to claim 30 or 31, wherein in the step (B1), the angle between the horizontal plane and the placement surface of the electrolysis electrode on the separator is 0 ° or more and less than 90 °.

33. The method of producing an electrolytic cell according to any one of claims 30 to 32, wherein in the step (B1), the electrolysis electrode is positioned so that the electrolysis electrode covers a current-carrying surface on the separator.

34. The method of any one of claims 30 to 33, wherein an amount of the aqueous solution adhering to the electrolysis electrode per unit area is 1g/m ²～1000g/m²。

35. The method of producing an electrolytic cell according to any one of claims 30 to 34, wherein a roll body obtained by winding the electrode for electrolysis is used in the step (B1).

36. The method of manufacturing an electrolytic cell according to claim 35, wherein in the step (B1), the wound state of the roll is released on the separator.

37. A method for manufacturing an electrolytic cell by disposing an electrode for electrolysis and a new diaphragm in an existing electrolytic cell including an anode, a cathode facing the anode, a diaphragm disposed between the anode and the cathode, and an electrolytic cell frame including an anode frame supporting the anode and a cathode frame supporting the cathode, and accommodating the anode, the cathode, and the diaphragm by integrating the anode frame and the cathode frame, the method comprising:

a step (A2) of releasing the integration of the anode frame and the cathode frame and exposing the separator;

a step (B2) of removing the separator after the step (a2) and disposing the electrolysis electrode and a new separator on the anode or the cathode; and

And a step (C2) of integrating the anode frame and the cathode frame to house the anode, the cathode, the separator, the electrode for electrolysis, and a new separator in the electrolysis cell frame.

38. The method of manufacturing an electrolytic cell according to claim 37, wherein in the step (B2), the electrolysis electrode is placed on the anode or the cathode, and the new separator is placed on the electrolysis electrode to planarize the new separator.

39. The method of manufacturing an electrolytic cell according to claim 38, wherein in the step (B2), the contact pressure of the flattening unit against the new diaphragm is 0.1gf/cm²～1000gf/cm²。

Technical Field

The invention relates to a jig for manufacturing a laminate, a method for manufacturing a laminate, a package, a laminate, an electrolytic cell, and a method for manufacturing an electrolytic cell.

Background

In the electrolysis of an aqueous solution of an alkali metal chloride such as a salt solution or the like or in the electrolysis of water (hereinafter referred to as "electrolysis"), a method using an electrolytic cell provided with a diaphragm, more specifically, an ion exchange membrane or a microporous membrane is used.

In many cases, the electrolytic cell includes a large number of electrolytic cells connected in series inside the electrolytic cell. Electrolysis is performed with a separator interposed between the electrolysis cells.

In the electrolytic cell, a cathode chamber having a cathode and an anode chamber having an anode are disposed back to back with a partition wall (back plate) interposed therebetween or pressed by a pressing pressure, a bolt fastening, or the like.

Conventionally, anodes and cathodes used in these electrolytic cells are fixed to anode chambers and cathode chambers of the respective electrolytic cells by welding, sandwiching, or the like, and then stored and transported to customers.

On the other hand, the separator is stored and transported to a customer in a state where it is wound around a pipe or the like made of vinyl chloride (polyvinyl chloride) alone. At the customer site, the cell is assembled by arranging the cells on the frame of the cell with the membrane sandwiched between the cells. The manufacture of the electrolysis cell and the assembly of the electrolysis cell at the customer site are thus carried out.

As a structure applicable to such an electrolytic cell, patent documents 1 and 2 disclose a structure in which a separator and an electrode are integrated.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 58-048686

Patent document 2: japanese laid-open patent publication No. 55-148775

Disclosure of Invention

Problems to be solved by the invention

When the electrolysis operation is started and continued, various factors deteriorate the respective members, the electrolysis performance is lowered, and the respective members are replaced at a certain time.

The membrane can be relatively easily renewed by withdrawing it from the electrolysis cell and inserting a new membrane.

On the other hand, since the anode and the cathode are fixed to the electrolytic cell, there is a problem that such a very complicated operation is caused when the electrode is renewed, the electrolytic cell is taken out from the electrolytic cell, the electrolytic cell is carried out to a dedicated renewal workshop, the electrode is removed and fixed by welding or the like to peel off the old electrode, and then the new electrode is installed and fixed by welding or the like, carried to the electrolytic workshop, and returned to the electrolytic cell.

In the above-described recent proposals, a structure in which the separator and the electrode are integrated by thermocompression bonding as described in patent documents 1 and 2 is considered, but the structure can be relatively easily manufactured at a laboratory level, but it is not easy to manufacture the structure in accordance with an electrolytic cell of a practical commercial size (for example, 1.5m in length and 3m in width). Further, the structure has a problem that the structure is not practically usable because the structure is completely peeled off when used for electrolysis for a long period of time because the structure is significantly deteriorated in electrolysis performance (such as electrolysis voltage, current efficiency, and salt concentration in sodium hydroxide) and durability and chlorine gas and hydrogen gas are generated at the electrodes at the interface between the separator and the structure.

The present invention has been made in view of the problems of the conventional techniques described above, and an object thereof is to provide a jig for producing a laminate, a method for producing a laminate, a package, a laminate, an electrolytic cell, and a method for producing an electrolytic cell, which are described below.

(purpose 1)

An object of the present invention is to provide a jig for manufacturing a laminate, a method for manufacturing a laminate, and a package, which are used for manufacturing a laminate capable of improving the work efficiency in the replacement of an electrode and a separator in an electrolytic cell.

(purpose 2)

An object of the present invention is to provide a laminate, an electrolytic cell, and a method for manufacturing an electrolytic cell, which are different from the above-described object 1, and which can suppress an increase in voltage and a decrease in current efficiency, can exhibit excellent electrolytic performance, can improve the work efficiency in electrode renewal in an electrolytic cell, and can exhibit excellent electrolytic performance even after the electrode renewal.

(purpose 3)

An object of the present invention is to provide a method for manufacturing an electrolytic cell, which is different from the above-described objects 1 and 2 and can improve the operation efficiency in the electrode renewal in the electrolytic cell.

Means for solving the problems

As a result of intensive studies to achieve the object 1, the present inventors have found that a member which can be easily transported and handled and which can greatly simplify the work for renewing the deteriorated member in the electrolytic bath can be obtained by winding and stacking a separator such as an ion exchange membrane or a microporous membrane and an electrode for electrolysis separately from a specific roll, and have completed the present invention.

That is, the present invention includes the following aspects.

[1]

A jig for producing a laminate of an electrode for electrolysis and a separator,

the jig comprises:

electrode roll around which a long electrolysis electrode is wound, and

a separator roll around which a long separator is wound.

[2]

The jig for producing a laminate as set forth in [1], further comprising:

and a water retention unit configured to supply water to at least one of the electrode roll, the separator roll, the electrolysis electrode wound from the electrode roll, and the separator wound from the separator roll.

[3]

The jig for producing a laminate according to [2], wherein the water retention means includes an impregnation tank for impregnating the electrode roll and/or the separator roll.

[4]

The jig for producing a laminated body according to [2] or [3], wherein the water retention means includes a spray head.

[5]

The jig for producing a laminated body according to any one of [2] to [4], wherein the water retention unit includes a sponge roller containing water.

[6]

The jig for producing a laminate according to any one of [1] to [5], further comprising:

and a positioning unit for fixing the relative position of the electrode roller and the diaphragm roller.

[7]

The jig for producing a laminated body according to [6], wherein the positioning means presses the electrode roller and the separator roller against each other by a spring.

[8]

The jig for producing a laminated body according to [6], wherein the positioning means fixes the positions of the electrode roller and the separator roller so that one of the electrode roller and the separator roller presses the other by its own weight.

[9]

The jig for producing a laminate as described in [6], wherein,

the electrode roll and the separator roll each have a rotation axis,

the positioning unit has a bearing portion for the rotating shaft.

[10]

The jig for producing a laminate according to any one of [1] to [9], further comprising:

and a rolling roll for pressing at least one of the electrode and the separator, which are wound out from the electrode roll and the separator roll, respectively.

[11]

The jig for producing a laminate according to any one of [1] to [10], further comprising:

and guide rollers for guiding the electrode and the separator, which are respectively wound from the electrode roller and the separator roller.

[12]

A method for producing a laminate of an electrode for electrolysis and a separator, comprising the steps of:

A step of winding up the electrolysis electrode from an electrode roll around which the long electrolysis electrode is wound; and

and a step of winding the separator from a separator roll around which the long separator is wound.

[13]

The method for producing a laminate according to [12], wherein the electrolysis electrode is brought into contact with the separator roller at a wrap angle of 0 to 270 ° and conveyed.

[14]

The method for producing a laminate according to [12], wherein the separator is in contact with the electrode roll at a wrap angle of 0 ° to 270 ° and is transported.

[15]

The method for producing a laminate as described in [12], wherein,

in the step of winding out the electrode and/or the separator for electrolysis, the electrode and/or the separator for electrolysis is guided by a guide roll;

the electrode for electrolysis is in contact with the guide roll at a wrap angle of 0 to 270 DEG and is conveyed.

[16]

The method for producing a laminate as described in [12], wherein,

in the step of winding out the electrode and/or the separator for electrolysis, the electrode and/or the separator for electrolysis is guided by a guide roll;

the diaphragm is contacted with the guide roller at a wrap angle of 0-270 degrees for transmission.

[17]

The method for producing a laminate according to any one of [12] to [16], further comprising:

And a step of supplying water to the electrolysis electrode wound from the electrode roll.

[18]

The method for producing a laminate according to any one of [12] to [17], wherein the wound electrode for electrolysis and separator are respectively wound out with relative positions of the electrode roll and the separator roll fixed.

[19]

A package is provided with:

an electrode roll around which a long electrolysis electrode is wound and/or a separator roll around which a long separator is wound; and

and a housing for housing the electrode roller and/or the separator roller.

The present inventors have made extensive studies to achieve the object of the invention of the present application, and as a result, have found that the above problems can be solved by using a separator having an uneven structure on the surface thereof and satisfying specific conditions, and have completed the present invention.

That is, the present invention includes the following aspects.

[20]

A laminate comprising:

an electrode for electrolysis; and

a separator laminated on a surface of the electrode for electrolysis,

wherein the content of the first and second substances,

the separator has a concavo-convex structure on the surface thereof,

the ratio a of the volume of the gap between the electrolysis electrode and the separator to the unit area of the separator is greater than 0.8 μm and not greater than 200 μm.

[21]

The laminate according to [20], wherein a height difference, which is a difference between a maximum value and a minimum value of the height in the textured structure, is larger than 2.5 μm.

[22]

The laminate according to [20] or [21], wherein a standard deviation of the level difference in the uneven structure is larger than 0.3 μm.

[23]

Such as [20]]～[22]The laminate according to any one of the above, wherein the interfacial water content w held at the interface between the separator and the electrolysis electrode is 30g/m²Above 200g/m²The following.

[24]

The laminate according to [20] to [23],

the electrode for electrolysis has 1 or a plurality of undulation portions on the opposite surface facing the diaphragm,

the undulation portion satisfies the following conditions (i) to (iii).

0.04≦S_a/S_all≦0.55…(i)

0.010mm²≦S_ave≦10.0mm²…(ii)

1<(h+t)/t≦10…(iii)

(in the above-mentioned (i), S_aThe total area S of the undulation portion in an observation image obtained by observing the facing surface with an optical microscope_allShowing the area of the facing surface in the observation image,

in the above (ii), S_aveRepresents an average area of the undulation portion in the observation image,

in the above (iii), h represents the height of the undulation portion, and t represents the thickness of the electrolysis electrode. )

[25]

The laminate according to [24], wherein the undulations are independently arranged in one direction D1 in the opposing plane.

[26]

The laminate as recited in [24] or [25], wherein the undulation portions are continuously arranged in one direction D2 in the opposing surfaces.

[27]

Such as [24]]～[26]The laminate according to any one of the above, wherein the mass per unit area of the electrode for electrolysis is 500mg/cm²The following.

[28]

An electrolytic cell comprising the laminate according to any one of [24] to [27 ].

[29]

A method for manufacturing a new electrolytic cell by disposing a laminate in an existing electrolytic cell including an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode,

the method comprises a step of exchanging the separator with the laminate in the conventional electrolytic cell,

the laminate is any one of the laminates according to [20] to [27 ].

The present inventors have made extensive studies to achieve the object of the present invention of the present application, and as a result, have found that the above problems can be solved by a method of renewing the performance of an electrode in an existing electrolytic cell without removing the existing electrode, and have completed the present invention.

That is, the present invention includes the following aspects.

[30]

A method for manufacturing an electrolytic cell by disposing an electrode for electrolysis in an existing electrolytic cell including an anode, a cathode facing the anode, a separator disposed between the anode and the cathode, and an electrolytic cell frame including an anode frame supporting the anode and a cathode frame supporting the cathode, the anode, the cathode, and the separator being accommodated by integrating the anode frame and the cathode frame, the method comprising:

A step (A1) of releasing the integration of the anode frame and the cathode frame and exposing the separator;

a step (B1) of disposing the electrolysis electrode on at least one surface of the separator after the step (a 1); and

and a step (C1) of integrating the anode frame and the cathode frame after the step (B1) to house the anode, the cathode, the separator, and the electrolysis electrode in the electrolysis cell frame.

[31]

The method of producing an electrolytic cell according to [30], wherein the electrolysis electrode and/or the separator are wetted with an aqueous solution before the step (B1).

[32]

The method of producing an electrolytic cell according to [30] or [31], wherein in the step (B1), an angle between the electrolytic electrode and a horizontal plane with respect to a surface on which the separator is placed is 0 ° or more and less than 90 °.

[33]

The method of producing an electrolytic cell according to any one of [30] to [32], wherein in the step (B1), the electrolysis electrode is positioned so that the electrolysis electrode covers an energization surface on the separator.

[34]

Such as [30]]～[33]The method of any one of the above-mentioned aspects, wherein an amount of the aqueous solution adhering to the electrolysis electrode per unit area is 1g/m ²～1000g/m²。

[35]

The method of producing an electrolytic cell according to any one of [30] to [34], wherein a roll body obtained by winding the electrolysis electrode is used in the step (B1).

[36]

The method of producing an electrolytic cell according to [35], wherein the wound state of the roll is released on the separator in the step (B1).

[37]

A method for manufacturing an electrolytic cell by disposing an electrode for electrolysis and a new separator in an existing electrolytic cell including an anode, a cathode facing the anode, a separator disposed between the anode and the cathode, and an electrolytic cell frame including an anode frame supporting the anode and a cathode frame supporting the cathode, the anode, the cathode, and the separator being accommodated by integrating the anode frame and the cathode frame, the method comprising:

a step (A2) of releasing the integration of the anode frame and the cathode frame and exposing the separator;

a step (B2) of removing the separator after the step (a2) and disposing the electrolysis electrode and a new separator on the anode or the cathode; and

And a step (C2) of integrating the anode frame and the cathode frame to house the anode, the cathode, the separator, the electrode for electrolysis, and a new separator in the electrolysis cell frame.

[38]

The method of producing an electrolytic cell according to [37], wherein in the step (B2), the electrolysis electrode is placed on the anode or the cathode, and the new separator is placed on the electrolysis electrode to planarize the new separator.

[39]

Such as [38 ]]The method of producing an electrolytic cell as described in (B2), wherein in the step (B2), the contact pressure of the flattening unit against the new separator is 0.1gf/cm²～1000gf/cm²。

ADVANTAGEOUS EFFECTS OF INVENTION

(1) According to the jig for manufacturing a laminate of the present invention, a laminate capable of improving the work efficiency in the renewal of the electrodes and separators in the electrolytic cell can be manufactured.

(2) According to the laminate of the present invention, it is possible to suppress an increase in voltage and a decrease in current efficiency, to improve the operation efficiency at the time of electrode renewal in an electrolytic cell, and to exhibit excellent electrolytic performance even after the renewal.

(3) According to the method for manufacturing an electrolytic cell of the present invention, the work efficiency in the electrode renewal in the electrolytic cell can be improved.

Drawings

(view corresponding to embodiment 1)

Fig. 1 (a) is a schematic view showing an electrode roll around which an electrolysis electrode is wound in embodiment 1. Fig. 1 (B) is a schematic view showing a separator roll around which a separator is wound according to embodiment 1. Fig. 1 (C) is a schematic view showing an example of the jig for producing a multilayer body according to embodiment 1.

Fig. 2 shows a schematic diagram of an example of using a spray head as the water-retaining unit in embodiment 1.

Fig. 3 (a) and (B) are schematic diagrams showing an example of using a sponge roller as the water-retaining unit in embodiment 1.

Fig. 4(a) is a schematic explanatory view of the jig for manufacturing a multilayer body in a mode (i) described later in plan view. Fig. 4 (B) is a schematic explanatory view of the multilayer body manufacturing jig shown in fig. 4(a) when viewed from the front in the X direction of fig. 4 (a).

Fig. 5 is a schematic explanatory view of a multilayer body manufacturing jig according to the embodiment (ii) to be described later, as viewed from the side.

Fig. 6 is a schematic explanatory view of a multilayer body manufacturing jig of the embodiment (iii) described later, as viewed from the side.

Fig. 7 is a schematic view showing an example in which the jig for manufacturing a multilayer body according to embodiment 1 is provided with guide rollers.

Fig. 8 is a schematic view showing an example in which the jig for manufacturing a multilayer body according to embodiment 1 is provided with guide rollers.

Fig. 9 is a schematic view showing an example in which the jig for manufacturing a laminate according to embodiment 1 is provided with a roll.

Fig. 10 is a schematic cross-sectional view showing one embodiment of the electrolysis electrode in embodiment 1.

Fig. 11 is a schematic sectional view showing an embodiment of the ion exchange membrane according to embodiment 1.

Fig. 12 is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion-exchange membrane in embodiment 1.

Fig. 13 shows a schematic view for explaining a method of forming the communicating holes of the ion-exchange membrane in embodiment 1.

Fig. 14 shows a schematic cross-sectional view of the electrolysis cell in embodiment 1.

Fig. 15 is a schematic cross-sectional view showing a state in which 2 electrolytic cells in embodiment 1 are connected in series.

FIG. 16 shows a schematic view of an electrolytic cell in embodiment 1.

FIG. 17 is a schematic perspective view showing an assembly process of the electrolytic cell in embodiment 1.

Fig. 18 is a schematic cross-sectional view of a reverse current absorber provided in the electrolytic cell of embodiment 1.

(view corresponding to embodiment 2)

Fig. 19 is a schematic cross-sectional view showing an example of the electrolysis electrode in embodiment 2.

FIG. 20 is a schematic sectional view showing another example of the electrolysis electrode according to embodiment 2.

FIG. 21 is a schematic cross-sectional view showing another example of the electrolysis electrode according to embodiment 2.

FIG. 22 is a plan perspective view of the electrolysis electrode shown in FIG. 19.

FIG. 23 is a plan perspective view of the electrolysis electrode shown in FIG. 20.

Fig. 24 (a) is a schematic view partially showing an example of a surface of a metal roll that can be used for producing an electrolysis electrode in embodiment 2, and fig. 24 (B) is a schematic view partially illustrating a surface of an electrolysis electrode in which a corrugated portion is formed by the metal roll in fig. 24 (a).

Fig. 25 shows a schematic view partially showing the surface of another example of a metal roll that can be used for the production of the electrolysis electrode in embodiment 2.

Fig. 26 shows a schematic view partially showing the surface of another example of a metal roll that can be used for the production of the electrolysis electrode in embodiment 2.

Fig. 27 shows a schematic view partially showing the surface of another example of a metal roll usable for the production of an electrolysis electrode in embodiment 2.

(view corresponding to embodiment 3)

Fig. 28 is a schematic sectional view of an electrolysis cell in embodiment 3.

FIG. 29 is a schematic view of an electrolytic cell in embodiment 3.

FIG. 30 is a schematic perspective view showing an assembly process of the electrolytic cell in embodiment 3.

Fig. 31 is a schematic cross-sectional view of a reverse current absorber that can be provided to the electrolytic cell in embodiment 3.

FIG. 32 is an explanatory view showing, by way of example, the respective steps in the method for producing an electrolytic cell according to embodiment 3.

FIG. 33 is an explanatory view showing, by way of example, the respective steps in the method for producing an electrolytic cell according to embodiment 3.

(drawing corresponding to example of embodiment 1)

Fig. 34 shows a schematic view of the roll 1 as a separator roll.

Fig. 35 shows a schematic view of the roll body 2 as a roller for electrodes.

Fig. 36 is a schematic view showing a process for producing a laminate in example 1.

Fig. 37 is a schematic view showing a process for producing a laminate in example 2.

Fig. 38 is a schematic view showing a process for producing a laminate according to example 3.

Fig. 39 is a schematic view showing a process for producing a laminate according to example 3.

Fig. 40 is a schematic view showing a process for producing a laminate according to example 4.

Fig. 41 is a schematic view showing a process for producing a laminate in example 5.

Fig. 42 is a schematic view showing a process for producing a laminate in example 5.

Fig. 43 is a schematic view showing a process for producing a laminate in example 6.

Fig. 44 is a schematic view showing a process for producing a laminate according to example 7.

(drawing corresponding to example of embodiment 2)

FIG. 45 is a diagram illustrating a method of measuring the ratio a used in examples.

FIG. 46 is an explanatory view of a method of measuring the ratio "a" used in examples.

FIG. 47 is a diagram illustrating a method of measuring the ratio a used in the examples.

FIG. 48 is an explanatory view of the method for measuring the ratio "a" used in examples.

FIG. 49 is a diagram illustrating a method of measuring the ratio a used in the examples.

FIG. 50 is a diagram illustrating a method of measuring the ratio a used in examples.

FIG. 51 is a diagram illustrating a method of measuring the ratio "a" used in examples.

Detailed Description

Hereinafter, embodiments of the present invention (hereinafter also referred to as the present embodiment) will be described in detail with reference to the drawings in the order of < embodiment 1 >, < embodiment 2 >, and < embodiment 3 >, as necessary. The present embodiment is an example for explaining the present invention, and the present invention is not limited to the following. The present invention can be suitably modified and implemented within the scope of the gist thereof.

The drawings show an example of the present embodiment, and the present embodiment is not to be construed as limited thereto. In the drawings, positional relationships such as vertical, horizontal, and the like are based on the positional relationships shown in the drawings unless otherwise specified. The dimensions and proportions of the figures are not limited to those shown.

< embodiment 1 >

Embodiment 1 of the present invention will be described in detail below.

[ jig for producing laminate ]

The jig for manufacturing a laminate according to embodiment 1 is used for manufacturing a laminate of an electrolysis electrode and a separator, and includes an electrode roll around which a long electrolysis electrode is wound and a separator roll around which a long separator is wound. With the above-described structure, the laminate manufacturing jig of embodiment 1 can manufacture a laminate which can improve the work efficiency in the replacement of the electrodes and separators in the electrolytic cell. That is, even in the case where a relatively large-sized member is required in accordance with an electrolytic cell of a practical commercial size (for example, 1.5m in length and 3m in width), a desired laminate can be easily obtained by a simple operation of arranging and fixing the electrode roller and the separator roller at desired positions and winding the electrode and the separator for electrolysis off the respective rollers.

In the present specification, the "strip" means a strip having a length sufficient to be wound around a roll having a specific diameter, and the width and length may be appropriately set according to the size of the electrolytic cell in which the laminate is assembled.

Specifically, the width of the separator and the electrode for electrolysis is preferably 200 to 2000mm, and the length thereof is preferably 500 to 4000 mm.

More preferably, they have a width of 300 to 1800mm and a length of 1200 to 3800 mm.

The length of the separator and the electrolysis electrode may be, for example, about 10m, which is a length corresponding to five sheets of about 2500mm, wound from each of the electrode roll and the separator roll (hereinafter, also referred to as "rolls"), and cut into a predetermined size.

The size, shape, material, and surface smoothness of the electrode roll and the separator roll are not particularly limited.

Specifically, the size of each roller can be adjusted appropriately according to the size of the separator and the size of the electrode for electrolysis. The cross-sectional shape of each roll may be circular, elliptical, polygonal having a square or more, or the like, and may be any shape that does not cause wrinkles or winding marks even when the separator or the electrolysis electrode is wound. The material of each roller may be either metal or resin, and is preferably resin in terms of conveyance weight. The smoothness of the surface of each roller may be such that the separator or the electrolysis electrode is not damaged even when wound. In addition, various known spreader rolls can be applied to each roll in order to more effectively suppress the occurrence of wrinkles.

Fig. 1 (a) is a schematic cross-sectional view of an electrode roll 100 around which an elongated electrode 101 for electrolysis is wound.

In fig. 1 (a), the electrolysis electrode 101 is shown by a broken line.

Fig. 1 (B) shows a schematic cross-sectional view of a separator roll 200 around which an elongated separator 201 is wound.

In fig. 1 (B), the diaphragm 201 is indicated by a solid line.

The electrolysis electrode 101 and the separator 201 are wound around a resin (for example, polyvinyl chloride) pipe 300 having a specific diameter.

In fig. 1, "+" indicates a rotation axis, and the same applies to the following drawings.

The laminate manufacturing jig of embodiment 1 includes, for example, as shown in fig. 1 (C), an electrode roll 100 around which an electrolysis electrode 101 is wound, and a separator roll 200 around which a separator 201 is wound, and can easily obtain the laminate 110 by winding out the electrolysis electrode 101 from the electrode roll 100, winding out the separator 201 from the separator roll 200, and laminating the electrolysis electrode 101 and the separator 201.

The laminate manufacturing jig according to embodiment 1 preferably further includes a water retention unit for supplying water to at least one of the electrode roll, the separator roll, the electrolysis electrode wound out of the electrode roll, and the separator wound out of the separator roll. In the case where the water retention unit is provided, in a state where the electrolysis electrode and the separator wound from the respective rolls are joined and brought into contact with each other, moisture is present at the interface between the electrolysis electrode and the separator, and the electrolysis electrode and the separator are easily integrated by the surface tension generated by the moisture.

As the moisture, pure water may be used, or an aqueous solution may be used. Examples of the aqueous solution include, but are not limited to, alkaline aqueous solutions (e.g., aqueous sodium bicarbonate solution, aqueous sodium hydroxide solution, aqueous potassium hydroxide solution, etc.).

The water retention means in embodiment 1 is not particularly limited as long as it can supply water as described above, and may have various configurations, and preferably includes an immersion tank for immersing the electrode roll and/or the separator roll.

In the case where the immersion tank is provided, it is possible to supply water to at least one of the electrode roll, the separator roll, the electrode for electrolysis wound out of the electrode roll, and the separator wound out of the separator roll by a simple operation of immersing the rolls.

The impregnation tank in embodiment 1 is not limited in shape, capacity, and the like as long as at least a part of the electrode roll and/or the separator roll can be impregnated.

In the case where the immersion tank is provided, the rolls may be immersed, then the rolls may be taken out of the immersion tank, and then the electrode and/or the separator for electrolysis may be wound out.

In the water retention unit according to embodiment 1, it is preferable to include a spray head instead of the immersion tank or in addition to the immersion tank. When water is sprayed from the spray head, the supply position, the amount of water, and the water pressure of water can be easily adjusted. The type of the spray head is not particularly limited, and may include at least one selected from the group consisting of a fan nozzle, a circular nozzle, and a circular nozzle. Specific examples thereof include, but are not limited to, solid conical nozzles, solid square conical nozzles, fan nozzles, flat nozzles, straight nozzles, nozzles with variable spray shapes, and the like available from Misumi corporation. In embodiment 1, the water retention unit preferably has a regulator in order to adjust the water pressure of the spray head. For example, in the case where a regulator is used in combination with a water pressure gauge in the water retention unit, it is more preferable that the water pressure be adjusted. Specific examples of the regulator include, but are not limited to, a water regulator WR2 manufactured by CKD corporation.

In addition, from the viewpoint of more efficiently producing a laminate by supplying sufficient moisture between the electrolysis electrode and the separator, when supplying moisture from the spray head, it is preferable to adjust various spray conditions in consideration of wettability of the moisture itself, shape of the electrolysis electrode, size of the electrolysis electrode, surface composition of the electrolysis electrode, and the like. More specifically, for example, it is preferable to adjust various conditions such as the distance between the separator or the electrolysis electrode and the spray head, the water pressure of the spray head, the water amount of the spray head, the position of the spray head, the angle of water spray, and the average droplet diameter at the time of spraying, in consideration of the above-mentioned factors.

Fig. 2 shows an example of a case where the jig for manufacturing a multilayer body according to embodiment 1 further includes a water retention means.

The jig for producing a laminate in the example of fig. 2 includes an electrode roll 100 around which an electrolysis electrode 101 is wound, a separator roll 200 around which a separator 201 is wound, and a water retention unit 450, and the electrolysis electrode 101 wound out from the electrode roll 100 may be an electrode having an opening, for example, and the water retention unit 450 supplies water 451 to the electrolysis electrode 101 having an opening. The moisture supplied to the electrolysis electrode 101 reaches the separator 201 side through the opening, and thereby surface tension due to the moisture is generated at the interface between the electrolysis electrode 101 and the separator 201, and the electrolysis electrode 101 and the separator 201 are naturally integrated to obtain the laminate 110. Although fig. 2 shows an example of supplying moisture to the electrolysis electrode 101 side, the water retention unit 450 may be arranged to supply moisture to the separator 201 side.

In embodiment 1, when the water retention means includes the spray heads, it is preferable to adjust the arrangement and number of the spray heads so that the water can be uniformly supplied from the spray heads to the rollers when the roller for the electrode and the roller for the diaphragm are provided so that the respective axial directions thereof are parallel to the ground surface.

In view of the efficiency of supplying water, it is preferable that the electrode roll and the separator roll are provided so that the respective axial directions are perpendicular to the ground surface, that is, that the water is supplied in a state where the electrode roll and the separator roll stand upright on the ground surface. In this case, the moisture sprayed from the spray head reaches the separator or the electrolysis electrode and then diffuses downward by the action of gravity, and by utilizing this, the moisture can be sufficiently distributed even at positions other than the spray position on the surface of the separator or the electrolysis electrode. That is, it is not necessary to directly spray moisture on the lower surface (ground side) of the separator or the electrode for electrolysis, and moisture can be effectively spread over the entire surface of the separator or the electrode for electrolysis by spraying moisture on the upper portion in the height direction.

The water retention unit in embodiment 1 preferably includes a sponge roller containing water instead of or in addition to the immersion tank and the spray head. An example when a sponge roller is used as the water retention unit is shown in fig. 3. The sponge roller 452 may be in contact with only the electrode roller 100 as shown in fig. 3 (a), or the sponge roller 452 may be in contact with both the electrode roller 100 and the separator roller 200 as shown in fig. 3 (B). Although not shown, the sponge roller 452 may be in contact with only the separator roller 200.

When the electrolysis electrode and the separator are integrated with each other by the moisture on the electrolysis electrode side, it is preferable to use the water retention means illustrated in fig. 3 (a) because the moisture can be easily supplied to the surface of the electrolysis electrode on the separator side even if the electrolysis electrode does not have an opening, for example. In the case of the embodiment illustrated in fig. 3(B), the same applies, and since water can be supplied to the surface of the separator on the side of the electrolysis electrode, a laminate tends to be obtained more easily.

The water retention means in embodiment 1 may include a flowing water supply means for supplying flowing water to the electrolysis electrode wound out from the electrode roll. That is, the water holding means is not limited to the spray head-containing type and the sponge roller-based type described above, and may supply water to the electrolysis electrode in a flowing state.

The water retention means in embodiment 1 may be, for example, a water tank or the like provided for submerging the separators and the electrolysis electrodes, which are fed out of the respective rolls, in a separated or stacked state, into water, in addition to the above-described means.

In embodiment 1, the relative positions of the electrode roller and the separator roller may be fixed by positioning means. The positioning means is not particularly limited as long as it can fix the relative position of the separator roller with respect to the electrode roller or the relative position of the electrode roller with respect to the separator roller, and may have various forms. As representative examples of the positioning means in embodiment 1, the following can be cited but are not limited: (i) a positioning unit having a mechanism for pressing the electrode roller and the separator roller against each other by a spring; (ii) a positioning unit for fixing the positions of the electrode roller and the diaphragm roller in a manner that one of the electrode roller and the diaphragm roller presses the other roller by the self weight; (iii) positioning means for fitting and fixing the rotating shaft to the corresponding bearing portion when the electrode roller and the separator roller each have a rotating shaft; and so on.

Even in the case of any one of the above (i) to (iii) and even in the case of using the positioning means which is not described in the above-mentioned patent document, the relative positions of the electrode roller and the separator roller are fixed, and thus a layered body tends to be obtained more stably. In the case where the jig for producing a laminate of embodiment 1 includes the water retention means in addition to the positioning means, in a state where the relative positions of the electrode roll and the separator roll are fixed and the electrolysis electrode and the separator wound from the rolls are joined and brought into contact with each other, moisture is present at the interface between the electrolysis electrode and the separator, and the electrolysis electrode and the separator are naturally integrated under surface tension caused by the moisture to obtain a laminate. The water content can be supplied to the separator or the electrode for electrolysis at any stage before and after the electrode for electrolysis and the separator, which are wound from the respective rolls, are joined and brought into contact with each other. Here, in the case where the electrolysis electrode and the separator are integrated with each other by the moisture on the electrolysis electrode side, if the electrolysis electrode has an opening, the moisture is likely to move through the opening, and the surface tension is likely to act on the interface between the electrolysis electrode and the separator, which is preferable. In particular, in the case where the electrolysis electrode and the separator wound out from the respective rolls are joined and brought into contact with each other to supply moisture to the electrolysis electrode, when the electrolysis electrode has an opening, the moisture supplied to the surface of the electrolysis electrode (the surface on the opposite side to the separator) reaches the surface on the side of the separator through the opening, and thus the surface tension from the moisture acts on the interface between the electrolysis electrode and the separator, which is particularly preferable.

The mode (i) will be described with reference to an example shown in fig. 4. Fig. 4 (a) is a schematic explanatory view of the multilayer body manufacturing jig 150 viewed from above. The jig 150 for manufacturing a laminate comprises: an electrode roller 100 and a separator roller 200 standing upright on the ground; a positioning unit 400 for fixing the relative positions of the electrode roller 100 and the separator roller 200; and a water retention unit 450.

As shown in fig. 4 (a), the positioning unit 400 has a pair of pressing plates 401a and 401b, and a spring mechanism 402 sandwiched therebetween. The spring mechanism 402 applies a force in the α direction to the pressing plate 401a and a force in the β direction to the pressing plate 401 b. Thereby, the contact portions of the electrode roller 100 and the separator roller 200 are pressed against each other, and are brought into close contact with each other. Fig. 4 (B) is a view of the laminated body manufacturing jig 150 as viewed from the front in the X direction in fig. 4 (a), and as shown in fig. 4 (B), the pair of pressing plates 401a and 401B are configured so as not to contact the electrolysis electrode 101 and the separator 201. In order to achieve this configuration, it is preferable that the electrode roll 100 is wound with the electrolysis electrode 101 around the vicinity of the axial center of the polyvinyl chloride pipe 300, that is, so that the surfaces of both ends of the polyvinyl chloride pipe 300 in the axial direction are exposed. As shown in fig. 4 (B), the force in the α direction applied to the electrode roll 100 acts not on the electrolysis electrode 101 in the electrode roll 100 but on the polyvinyl chloride pipe 300 (the portion where the electrolysis electrode 101 is not wound), and thus friction can be prevented from being generated between the electrolysis electrode 101 and the pressing plate 401 a. Similarly, it is preferable that the separator 201 is wound around the separator roller 200 in the vicinity of the axial center of the polyvinyl chloride pipe 300, that is, the separator 201 is wound so that the surfaces of both ends in the axial direction of the polyvinyl chloride pipe 300 are exposed. As shown in fig. 4 (B), the force in the β direction applied to the roll 200 for a separator acts not on the separator 201 in the roll 200 for a separator but on the tube 300 made of polyvinyl chloride (a portion where the separator 201 is not wound), whereby friction can be prevented from being generated between the separator 201 and the pressing plate 401B. As long as such an action is obtained, the pair of pressing plates 401a and 401b and the spring mechanism 402 are not particularly limited, and can be applied to embodiment 1 with reference to various known fixing means. The force acting on the electrode roller 100 and the separator roller 200 by the spring mechanism 402 is not particularly limited, and for example, in the embodiment (ii) described below, a force of the same degree as that in the case where one of the electrode roller and the separator roller is pressed against the other by its own weight may be applied. For example, in the case of using a polyvinyl chloride pipe having a width of 1500mm, a method of applying a force of about 1.2kgf may be used, but not limited thereto.

The electrode roll 100 and the separator roll 200 rotate in the direction r, respectively, and thereby the electrolysis electrode 101 and the separator 201 are wound out. In this embodiment, the electrode roll 100 and the separator roll 200 are in a state of being in close contact with each other as described above, and the electrode 101 and the separator 201 are wound out in this state, so that the generation of wrinkles tends to be more effectively suppressed. In view of this, in embodiment 1, the positioning means preferably presses the electrode roller and the separator roller against each other with a spring.

The rolled-up electrode 101 for electrolysis may be an electrode having an opening, for example, and the water retention unit 450 may supply the water 451 to the electrode 101 for electrolysis having an opening. The moisture supplied to the electrolysis electrode 101 reaches the separator 201 side through the opening, and thus surface tension due to the moisture is generated at the interface between the electrolysis electrode 101 and the separator 201, and the electrolysis electrode 101 and the separator 201 are naturally integrated to obtain the laminate 110.

The above description has been made on the case where the electrode roller 100 and the separator roller 200 stand upright on the ground (that is, the case where the rotation axis directions of the electrode roller 100 and the separator roller 200 are perpendicular to the ground), but the present invention is not limited to this, and for example, the same configuration may be employed even when the axial directions of the electrode roller 100 and the separator roller 200 are parallel to the ground. Although fig. 4 shows an example of supplying moisture to the electrolysis electrode 101 side, the water retention means 450 may be arranged to supply moisture to the separator 201 side.

The same applies to the respective constituent members of the jig 150 for producing a laminate as described above in the following embodiments unless otherwise specified.

The mode (ii) will be described with reference to an example shown in fig. 5. Fig. 5 is a schematic explanatory view of the multilayer body manufacturing jig 150 viewed from the side. The jig 150 for manufacturing a laminate includes the electrode roller 100 and the separator roller 200, the positioning unit 400 for fixing the relative positions of the electrode roller 100 and the separator roller 200, and the water retention unit 450, and in this embodiment, the electrode roller 100 and the separator roller 200 are arranged so that the rotation axis direction is parallel to the ground surface. In this embodiment, the electrode roller 100 and the separator roller 200 are not arranged in a state of standing upright on the ground but arranged so that their respective axial directions are parallel to the ground, in view of making them closely contact with each other by the weight of one of the electrode roller 100 and the separator roller 200.

In the example shown in fig. 5, the roller 100 for electrode presses the roller 200 for separator in the γ direction by its own weight (gravity). The positioning unit 400 functions as a frame member that wraps the electrode roller 100 and the separator roller 200, and the positioning unit 400 itself does not press the rollers, but the pressing of the separator roller 200 by the weight of the electrode roller 100 can be maintained by the positioning unit 400. Thereby, the contact portions of the electrode roller 100 and the separator roller 200 are pressed to be in a state of being in close contact with each other. In the example shown in fig. 5, it is preferable to adjust the shape of the positioning unit 400 in order to prevent friction due to contact between the electrolysis electrode 101 and the separator 201 and the positioning unit 400. For example, by adopting such a shape as the pressing plates 401a and 401B shown in (B) of fig. 4, it is possible to prevent the contact of the electrode 101 and the diaphragm 201 with the positioning unit 400.

Therefore, in this embodiment, the adhesion between the electrode roller and the separator roller is further improved, and the occurrence of wrinkles in the obtained laminate can be further suppressed. As described above, the positioning means preferably fixes the positions of the electrode roller and the separator roller so that one of the electrode roller and the separator roller presses the other by its own weight.

The positional relationship between the electrode roller 100 and the separator roller 200 may be reversed, and the electrode roller 100 may be pressed by the weight of the separator roller 200. In this case, the position of the water retention unit 450 may be appropriately adjusted so that the water 451 can be supplied to the electrolysis electrode 101.

The shape of the positioning unit 400 is not limited to the example of fig. 5, and various known shapes may be used as long as the pressing of one of the electrode roller and the separator roller against the other roller by its own weight can be maintained.

The mode (iii) will be described with reference to an example shown in fig. 6. Fig. 6 is a schematic explanatory view of the jig 150 for producing a multilayer body viewed from the side. The jig 150 for manufacturing a laminate includes the electrode roller 100 and the separator roller 200, a positioning unit 400 for fixing the relative positions of the electrode roller 100 and the separator roller 200, and a water holding unit 450. In this embodiment, the electrode roller 100 and the separator roller 200 each have a rotation axis, and are disposed so that their axis directions are parallel to the ground.

In the example shown in fig. 6, the positioning unit 400 has a bearing portion 403a corresponding to the electrode roller 100 and a bearing portion 403b corresponding to the separator roller 200, and the respective rotation shafts are fixed by the bearing portions 403a and 403b, whereby the adhesion between the electrode roller 100 and the separator roller 200 can be ensured. Here, the bearing portion refers to a protruding portion formed along the axial direction of each roller at both ends of the roller. Therefore, in this embodiment, the adhesion between the electrode roller and the separator roller is further improved, and the occurrence of wrinkles in the obtained laminate can be further suppressed. As described above, it is preferable that the electrode roller and the separator roller each have a rotating shaft, and the positioning means has a bearing portion of the rotating shaft.

As shown in the example of fig. 6, the bearing portion may be provided with a positioning means having a hole portion into which the rotary shaft of each roller can be fitted, but the bearing portion is not limited to this, and for example, a pair of plates may be provided as the positioning means, and each rotary shaft may be sandwiched between the pair of plates.

In this case, the position of the water retaining unit 450 may be appropriately adjusted so that the water 451 can be supplied to the electrolysis electrode 101.

Further, although the case where the axial directions of the electrode roller 100 and the separator roller 200 are parallel to the ground has been described above, the present invention is not limited to this, and the same configuration may be employed when the electrode roller 100 and the separator roller 200 stand upright on the ground, for example.

As illustrated in fig. 7 and 8, the jig for manufacturing a laminate according to embodiment 1 may further include a guide roller 302 for guiding the electrode for electrolysis and the separator, which are respectively wound off from the electrode roller and the separator roller. In fig. 7 and 8, the positions of the rollers 100 and 200 may be switched so that the guide roller 302 guides the diaphragm 201.

In fig. 7, the electrolysis electrode 101 is shown in a manner of being conveyed in contact with the separator roller 200 at a wrap angle θ.

In the present specification, the wrap angle is an angle between a starting point at which the separator, the electrode for electrolysis, or the laminate comes into contact with each specific roller and a contact end point at which the separator, the electrode for electrolysis, or the laminate starts to separate, with reference to a center point of a cross section of the roller.

In fig. 7, the wrap angle θ when the electrolysis electrode 101 and the separator roller 200 are conveyed while being in contact with each other at the wrap angle θ is preferably 0 ° to 270 °, more preferably 0 ° to 150 °, even more preferably 0 ° to 90 °, and even more preferably 10 ° to 90 °, from the viewpoint that the separator and the electrolysis electrode are in contact without wrinkles.

Fig. 8 shows a mode in which the electrolysis electrode 101 and the separator roller 200 are conveyed while being in contact with each other at a wrap angle of 0 °.

In fig. 7 and 8, the wrap angle when the electrode roll 100 and the separator roll 200 are exchanged in position and the separator 201 and the electrode roll 100 are brought into contact with each other at the wrap angle θ and conveyed is preferably 0 to 270 °, more preferably 0 to 150 °, even more preferably 0 to 90 °, and even more preferably 10 to 90 ° from the viewpoint that the separator and the electrode for electrolysis are brought into contact without wrinkles.

The wrap angle θ of the electrolytic electrode 101 and the separator 201 when they are in contact with the respective rollers can be controlled to a predetermined range by the drawing direction of the arrows shown in fig. 7 and 8.

In the example of fig. 7 and 8, the wrap angle θ when the electrolysis electrode 101 and the guide roll 302 are conveyed while being in contact with each other at the wrap angle θ is preferably 0 to 270 °, more preferably 0 to 150 °, even more preferably 0 to 90 °, and even more preferably 10 to 90 °, in terms of the fact that the separator and the electrolysis electrode are in contact without wrinkles.

In the example of fig. 7 and 8, the positions of the electrode roll 100 and the separator roll 200 may be switched, and in this case, the wrap angle of the separator 201 when it is conveyed while being in contact with the guide roll 302 at the wrap angle θ is preferably 0 ° to 270 °, more preferably 0 ° to 150 °, even more preferably 0 ° to 90 °, and even more preferably 10 ° to 90 °, from the viewpoint that the separator is in contact with the electrolysis electrode without wrinkles.

The wrap angle θ of the electrolytic electrode 101 and the separator 201 when they are in contact with the guide roll 302 can be controlled to a predetermined range by adjusting the drawing direction.

In embodiment 1, the method of producing a laminate by winding out the electrode 101 and the separator 201 from the electrode roll 100 and the separator roll 200, respectively, is not particularly limited, and for example, as shown in fig. 9, the electrode for electrolysis wound out from the electrode roll 100 and the separator 201 wound out from the separator roll 200 may be pressed so as to be sandwiched between the rolling roll 301 and the separator roll 200, and the laminate 110 may be obtained by transferring them. The positions of the rollers 100 and 200 in fig. 9 may be switched so that the electrode for electrolysis wound out from the electrode roller 100 and the separator 201 wound out from the separator roller 200 are sandwiched between the rolling roller 301 and the electrode roller 100, and the electrode and the separator are pressed and transferred to obtain the laminate 110.

[ method for producing a laminate ]

The method for manufacturing a laminate of an electrolysis electrode and a separator according to embodiment 1 includes a step of taking out an electrolysis electrode from an electrode roll around which the long electrolysis electrode is wound, and a step of taking out a separator from a separator roll around which the long separator is wound. With the above-described configuration, the method for producing a laminate according to embodiment 1 can produce a laminate that can improve the work efficiency in the case of replacing the electrodes and the separators in the electrolytic cell.

The method for manufacturing the laminate of embodiment 1 can be preferably performed by using the jig for manufacturing a laminate of embodiment 1.

In embodiment 1, from the viewpoint of more stable production of the laminate, the electrolysis electrode is preferably conveyed in contact with the separator roll at a wrap angle of 0 ° to 270 °. From the same viewpoint, the separator is preferably conveyed in contact with the electrode roll at a wrap angle of 0 ° to 270 °.

In embodiment 1, from the viewpoint of more stably producing a laminate, in the step of winding out the electrode and/or the separator for electrolysis, it is preferable that the electrode and/or the separator for electrolysis is guided by a guide roll, and the electrode for electrolysis is conveyed while being brought into contact with the guide roll at a wrap angle of 0 ° to 270 °. From the same viewpoint, in the step of winding out the electrode for electrolysis and/or the separator, it is also preferable that the electrode for electrolysis and/or the separator is guided by a guide roll, and the separator is conveyed by being brought into contact with the guide roll at a wrap angle of 0 ° to 270 °.

In embodiment 1, it is preferable to further include a step of supplying water to the electrolysis electrode wound from the electrode roll, in order to facilitate the production of the laminate.

In embodiment 1, from the viewpoint of more stably producing a laminate, it is preferable to separately wind the wound electrode for electrolysis and separator while fixing the relative positions of the electrode roll and the separator roll.

[ Package ]

The package of embodiment 1 includes an electrode roll around which an elongated electrode for electrolysis is wound and/or a separator roll around which an elongated separator is wound, and a case that houses the electrode roll and/or the separator roll. The package of embodiment 1 can be preferably used in the method for producing the laminate of embodiment 1. Examples of the package include a package including an electrode roll 100 around which an electrode 101 for electrolysis shown in fig. 1 (a) is wound, a separator roll 200 around which a separator 201 shown in fig. 1 (B) is wound, and a case that houses the electrode roll 100 and the separator roll 200.

As described above, the package of embodiment 1 may have the electrode roller 100 and the separator roller 200 in the same case, for example.

For example, a package having the electrode roller 100 in the case and a package having the separator roller 200 in the case may be prepared and used in the method for manufacturing the laminate of embodiment 1.

In the package according to embodiment 1, the case may have a specific slit for leading out and transmitting the electrolysis electrode 101 and/or the separator 201. The package according to embodiment 1 may further include a water retention means for supplying water to the separator 201.

When the electrode roll 100 and the separator roll 200 are housed in the same case, the electrode roll 100 and/or the separator roll 200 may be taken out of the case, the electrolysis electrode 101 may be wound out from the electrode roll 100, the separator 201 may be wound out from the separator roll 200, and the electrolysis electrode 101 and the separator 201 may be laminated to produce the laminated body 110 when producing the laminated body 110.

In the case where the electrode roll 100 and the separator roll 200 are housed in the same casing, when the layered body 110 is manufactured, the electrode 101 for electrolysis may be wound out from the electrode roll 100, the separator 201 may be wound out from the separator roll 200, and the electrode 101 for electrolysis and the separator 201 may be layered together in a state where the electrode roll 100 and the separator roll 200 are housed in the casing.

When the electrode roll 100 and the separator roll 200 are housed in separate casings, respectively, the electrode roll 100 and/or the separator roll 200 may be taken out of the respective casings, the electrolysis electrode 101 may be wound out from the electrode roll 100, the separator 201 may be wound out from the separator roll 200, and the electrolysis electrode 101 and the separator 201 may be laminated to produce the laminated body 110.

In the case where the electrode roll 100 and the separator roll 200 are housed in separate casings, respectively, when the laminated body 110 is manufactured, the electrode 101 for electrolysis may be wound out from the electrode roll 100 and the separator 201 may be wound out from the separator roll 200 in a state where the electrode roll 100 and the separator roll 200 are housed in separate casings, and the electrode 101 for electrolysis and the separator 201 may be laminated to manufacture the laminated body.

[ layered body ]

The laminate obtained by the jig for producing a laminate and/or the method for producing a laminate of embodiment 1 (hereinafter, sometimes referred to as "laminate of embodiment 1") includes an electrode for electrolysis and a separator in contact with the electrode for electrolysis.

Will be first1 the laminate of the embodiment, when assembled in an electrolytic cell, the force applied per unit mass and unit area of the electrolysis electrode is preferably less than 1.5N/mg cm to the separator or the power feeding body². With such a configuration, the laminate can improve the operation efficiency in the electrode renewal in the electrolytic cell, and can exhibit excellent electrolytic performance even after the renewal.

That is, when the electrode is refreshed by the laminate of embodiment 1, the electrode can be refreshed by the same simple operation as the refreshing of the separator without complicated operations such as peeling off the original electrode fixed to the electrolytic cell, and therefore, the operation efficiency can be greatly improved.

Further, the laminate of embodiment 1 can maintain or improve the electrolytic performance over that of a fresh product. Therefore, the electrode fixed to the new electrolytic cell of the related art and functioning as the anode and the cathode only needs to function as the power feeder, and the catalyst coating can be greatly reduced or eliminated.

The laminate according to embodiment 1 can be stored in a state (e.g., a roll) wound around a polyvinyl chloride pipe or the like and transported to a customer, and the handling thereof is very easy.

As the power feeder, various substrates described later, such as a deteriorated electrode (i.e., an existing electrode) and an electrode not coated with a catalyst, can be used.

The laminate according to embodiment 1 may have a fixing portion partially as long as it has the above-described structure. That is, in the case where the laminate of embodiment 1 has a fixed part, the part not having the fixed part is used for measurement, and the force applied per unit mass and unit area of the obtained electrode for electrolysis is preferably less than 1.5N/mg cm²。

[ electrode for electrolysis ]

The electrode for electrolysis constituting the laminate of embodiment 1 is excellent in handling properties and excellent in adhesion to a separator such as an ion exchange membrane or a microporous membrane, a power supply body (a deteriorated electrode and an electrode not coated with a catalyst), and the like The force applied per unit mass/unit area is preferably 1.6N/(mg/cm)²) Less than 1.6N/(mg. cm) is more preferable²) More preferably less than 1.5N/(mg. cm)²) More preferably 1.2N/mg/cm²The concentration is preferably 1.20N/mg/cm or less²The following. Still more preferably 1.1N/mg-cm²The concentration is preferably 1.10N/mg/cm or less²The lower, particularly preferred is 1.0N/mg-cm²The concentration is preferably 1.00N/mg cm²The following.

From the viewpoint of further improving the electrolytic performance, it is preferably more than 0.005N/(mg. cm)²) More preferably 0.08N/(mg. cm)²) More preferably 0.1N/mg-cm²More preferably 0.14N/(mg. cm)²) The above. From the viewpoint of facilitating handling in the case of a large size (for example, a size of 1.5m × 2.5m), it is more preferably 0.2N/(mg · cm)²) The above.

The above-mentioned applied force can be adjusted to the above-mentioned range by appropriately adjusting, for example, the aperture ratio, the thickness of the electrode for electrolysis, the arithmetic average surface roughness, and the like, which will be described later. More specifically, for example, when the opening ratio is increased, the applied force tends to decrease, and when the opening ratio is decreased, the applied force tends to increase.

In addition, from the viewpoint of obtaining good workability, having good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode, a catalyst-uncoated power feeder, or the like, and further from the viewpoint of economy, the mass per unit area is preferably 48mg/cm ²Less than, more preferably 30mg/cm²The concentration is preferably 20mg/cm or less²Hereinafter, from the viewpoint of comprehensive consideration of workability, adhesiveness and economy, it is preferably 15mg/cm²The following. The lower limit is not particularly limited, and is, for example, 1mg/cm²Left and right.

The mass per unit area can be set to the above range by appropriately adjusting, for example, the aperture ratio, the thickness of the electrode, and the like, which will be described later. More specifically, for example, if the thickness is the same, the mass per unit area tends to decrease when the open area ratio increases, and the mass per unit area tends to increase when the open area ratio decreases.

The force applied can be measured by the following method (i) or (ii).

The value obtained by the measurement by the method (i) (also referred to as "applied force (1)") and the value obtained by the measurement by the method (ii) (also referred to as "applied force (2)") may be the same or different with respect to the applied force, and both values may be less than 1.5N/mg · cm²。

[ method (i) ]

A sample for measurement was obtained by stacking in order a nickel plate (thickness 1.2mm, 200mm square) obtained by sand blasting using alumina of particle number 320, an ion exchange membrane (170mm square) in which inorganic particles and a binder were applied to both surfaces of a membrane of perfluorocarbon polymer having ion exchange groups introduced, and an electrode sample (130mm square), sufficiently immersing the stack in pure water, and then removing excess water adhering to the surface of the stack.

Here, as the ion exchange membrane, the ion exchange membrane a shown below was used.

As the reinforcing core material, a Polytetrafluoroethylene (PTFE) monofilament of 90 denier (hereinafter referred to as PTFE yarn) was used. As the sacrificial yarn, yarn obtained by twisting polyethylene terephthalate (PET) of 35 denier and 6 filaments at 200 times/m (hereinafter referred to as PET yarn) was used. First, in both TD and MD directions, a woven fabric was obtained by plain-weaving PTFE filaments at 24 filaments/inch and sacrificial filaments arranged at 2 filaments between adjacent PTFE filaments. The obtained woven fabric was pressed against a roller to obtain a reinforcing material as a woven fabric having a thickness of 70 μm.

Next, resin A (which is CF) which is a dried resin having an ion exchange capacity of 0.85mg equivalent/g was prepared₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOCH₃Copolymer of (B), resin B (which is CF) which is a dry resin having an ion exchange capacity of 1.03mg equivalent/g₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂Copolymers of F). Use of theseA2-layer film X having a resin A layer thickness of 15 μm and a resin B layer thickness of 84 μm was obtained by a co-extrusion T-die method using the resin A and the resin B. A single-layer film Y having a thickness of 20 μm was obtained by the T-die method using only the resin B.

Subsequently, a release paper (conical embossing having a height of 50 μm), a film Y, a reinforcing material, and a film X were sequentially laminated on a hot plate having a heating source and a vacuum source inside and having fine holes on the surface thereof, and the release paper was removed after heating and pressure reduction for 2 minutes under conditions of a hot plate surface temperature of 223 ℃ and a vacuum degree of 0.067MPa, thereby obtaining a composite film. The film X is laminated in the following manner with the resin B.

The resulting composite membrane was immersed in an aqueous solution at 80 ℃ containing 30 mass% of dimethyl sulfoxide (DMSO) and 15 mass% of potassium hydroxide (KOH) for 20 minutes to saponify the composite membrane, and then immersed in an aqueous solution at 50 ℃ containing 0.5N of sodium hydroxide (NaOH) for 1 hour to replace the counter ion of the ion exchange group with Na, followed by water washing. Thereafter, the surface of the side of the resin B was polished at a relative speed of 100 m/min and a pressing amount of 2mm to form an opening portion, and then dried at 60 ℃.

Further, 20 mass% of zirconia having a 1-order particle diameter of 1 μm was added to a 5 mass% ethanol solution of an acid resin of resin B, and dispersed to prepare a suspension, and the suspension was sprayed on both surfaces of the composite film by a suspension spraying method to form a zirconia coating layer on the surface of the composite film, thereby obtaining an ion exchange membrane a as a separator. Here, the coating density of zirconia measured by fluorescent X-ray measurement was 0.5mg/cm²。

The nickel plate after the sandblasting has an arithmetic average surface roughness (Ra) of 0.5 to 0.8 μm. A specific calculation method of the arithmetic average surface roughness (Ra) is as follows.

For the surface roughness measurement, a stylus surface roughness measuring instrument SJ-310 (Mitutoyo, K.K.) was used. The measurement sample was set on a surface plate parallel to the ground, and the arithmetic average roughness Ra was measured under the following measurement conditions. In the measurement, 6 measurements were performed, and the average value was defined as Ra.

< shape of contact pin > cone angle 60 °, tip radius 2 μm, and static measurement force 0.75mN

< roughness standard > JIS2001

< evaluation Curve > R

< Filter > GAUSS

< cut-off wavelength value λ c >0.8mm

< cut-off wavelength value λ s >2.5 μm

< number of intervals >5

< front walk, rear walk > have

Under the conditions of a temperature of 23. + -. 2 ℃ and a relative humidity of 30. + -. 5%, only the electrode sample among the above-mentioned measurement samples was raised by 10 mm/min in the vertical direction by using a tensile compression tester, and the load when the electrode sample was raised by 10mm in the vertical direction was measured. The measurement was performed 3 times, and an average value was calculated.

The average value was divided by the area of the portion of the electrode sample overlapping the ion exchange membrane and the mass of the electrode sample overlapping the ion exchange membrane to calculate the force (1) (N/mg. cm) applied per unit mass per unit area²)。

The applied force (1) per unit mass and unit area obtained by the method (i) is preferably less than 1.5N/mg cm in view of obtaining good workability and good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode, and a catalyst-uncoated power feeding body²More preferably 1.2N/mg-cm²The concentration is preferably 1.20N/mg cm or less ²The concentration is preferably 1.1N/mg/cm or less²The lower, more preferably 1.10N/mg cm²The concentration is preferably 1.0N/mg/cm or less²The concentration is preferably 1.00N/mg cm²The following.

In addition, from the viewpoint of further improving the electrolytic performance, it is preferably more than 0.005N/(mg. cm)²) More preferably 0.08N/(mg. cm)²) More preferably 0.1N/(mg. cm)²) As described above, the processing in the case of a large size (for example, a size of 1.5 m. times.2.5 m) is easyFrom the viewpoint of (1), more preferably 0.14N/(mg. cm)²) More preferably 0.2N/(mg. cm)²) The above.

When the electrolysis electrode satisfies the applied force (1), it can be used by being integrated with a separator such as an ion exchange membrane or a microporous membrane or a power supply body (that is, made into a laminate), and therefore, when the electrode is renewed, it is not necessary to perform a replacement operation of the cathode and the anode fixed to the electrolysis cell by a method such as welding, and the operation efficiency is greatly improved. Further, by using the electrode for electrolysis in the form of a laminate integrated with an ion exchange membrane, a microporous membrane, or a current-supplying body, the electrolytic performance can be made equal to that in the case of a new product or the electrolytic performance can be improved.

In the prior art, when a new electrolytic cell is shipped, the electrodes fixed to the electrolytic cell are coated with a catalyst, but the electrodes for electrolysis in embodiment 1 can be used as electrodes by combining only electrodes that are not coated with a catalyst, and therefore, the manufacturing process for coating with a catalyst and the amount of catalyst can be significantly reduced or eliminated. The original electrode in which the catalyst coating is significantly reduced or eliminated is electrically connected to the electrolysis electrode in embodiment 1, and can function as a power supply body for flowing current.

[ method (ii) ]

A nickel plate (nickel plate having a thickness of 1.2mm, 200mm square, the same as in the above method (i)) obtained by sand blasting using the alumina of grain number 320 and an electrode sample (130mm square) were laminated in this order, and the laminate was sufficiently immersed in pure water, and then excess water adhering to the surface of the laminate was removed, thereby obtaining a sample for measurement.

Under the conditions of a temperature of 23. + -. 2 ℃ and a relative humidity of 30. + -. 5%, only the electrode sample in the measurement sample was raised by 10 mm/min in the vertical direction by using a tensile compression tester, and the load when the electrode sample was raised by 10mm in the vertical direction was measured. The measurement was performed 3 times, and an average value was calculated.

The average value was divided by the area of the overlapping portion of the electrode sample and the nickel plate and the mass of the electrode sample in the portion overlapping the nickel plateThe adhesion (2) (N/mg. cm) per unit mass/unit area was calculated²)。

The applied force (2) per unit mass and unit area obtained by the method (ii) is preferably less than 1.5N/mg cm in view of obtaining good workability and good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode, and a catalyst-uncoated power feeding body ²More preferably 1.2N/mg-cm²The concentration is preferably 1.20N/mg cm or less²The concentration is preferably 1.1N/mg/cm or less²The lower, more preferably 1.10N/mg cm²The concentration is preferably 1.0N/mg/cm or less²The concentration is preferably 1.00N/mg cm²The following.

From the viewpoint of further improving the electrolytic performance, it is preferably more than 0.005N/(mg. cm)²) More preferably 0.08N/(mg. cm)²) More preferably 0.1N/(mg. cm)²) From the viewpoint of facilitating handling in a large size (for example, a size of 1.5m × 2.5m), the above-mentioned ratio is more preferably 0.14N/(mg · cm)²) The above.

When the electrolysis electrode in embodiment 1 satisfies the applied force (2), it can be stored and transported to a customer in a state (e.g., rolled) in which it is wound around a polyvinyl chloride pipe or the like, and the operation is very easy. Further, by attaching the electrode for electrolysis in embodiment 1 to a deteriorated original electrode to form a laminate, the electrolytic performance can be made equal to that in the case of a new product or the electrolytic performance can be improved.

In the case where the electrolysis electrode in embodiment 1 is an electrode having a wide elastically deformable region, the thickness of the electrolysis electrode is preferably 315 μm or less, more preferably 220 μm or less, further preferably 170 μm or less, further more preferably 150 μm or less, particularly preferably 145 μm or less, further preferably 140 μm or less, further still further preferably 138 μm or less, and further more preferably 135 μm or less, from the viewpoint of obtaining more excellent workability and more excellent adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode, a catalyst-uncoated power feeder, and the like.

When the thickness is 315 μm or less, good workability can be obtained.

From the same viewpoint as above, it is preferably 130 μm or less, more preferably less than 130 μm, still more preferably 115 μm or less, and still more preferably 65 μm or less. The lower limit is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, and still more preferably 20 μm or more from the practical viewpoint.

In embodiment 1, the phrase "elastically deformable region is wide" means that the electrolysis electrode is wound into a roll, and after the wound state is released, warping due to winding is less likely to occur. The thickness of the electrolysis electrode is the total thickness of the electrode base material for electrolysis and the catalyst layer when the catalyst layer described later is included.

The electrolysis electrode in embodiment 1 preferably includes an electrolysis electrode substrate and a catalyst layer.

The thickness (gauge thickness) of the electrode base material for electrolysis is not particularly limited, and is preferably 300 μm or less, more preferably 205 μm or less, further preferably 155 μm or less, further more preferably 135 μm or less, particularly preferably 125 μm or less, further preferably 120 μm or less, further more preferably 100 μm or less, and further more preferably 50 μm or less from the viewpoints of workability and economy, in order to obtain good workability, and to have good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode (power feeder), and an electrode (power feeder) to which no catalyst is applied, to be able to be suitably wound into a roll and folded well, and to facilitate handling in a large size (for example, a size of 1.5m × 2.5 m).

The lower limit is not particularly limited, but is, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

It is preferable that a liquid is interposed between a separator such as an ion exchange membrane or a microporous membrane and an electrode for electrolysis, or a porous metal plate or a metal plate (i.e., a power supply) such as a deteriorated existing electrode or an electrode not coated with a catalyst and an electrode for electrolysis.

Any liquid may be used as long as it is a liquid that can generate surface tension, such as water or an organic solvent. The larger the surface tension of the liquid, the larger the force applied between the separator and the electrode for electrolysis, or between the porous metal plate or the metal plate and the electrode for electrolysis, and therefore, a liquid having a large surface tension is preferred.

Examples of the liquid include the following (the value in parentheses is the surface tension of the liquid at 20 ℃).

Hexane (20.44mN/m), acetone (23.30mN/m), methanol (24.00mN/m), ethanol (24.05mN/m), ethylene glycol (50.21mN/m), water (72.76mN/m)

If the liquid has a large surface tension, the separator and the electrode for electrolysis, or the porous metal plate or the metal plate (power feeder) and the electrode for electrolysis are integrated (laminated), and the electrode can be easily replaced. The liquid between the separator and the electrode for electrolysis, or between the porous metal plate or the metal plate (power feeder) and the electrode for electrolysis may be in an amount of such a degree that the liquid adheres to each other by surface tension, and as a result, the amount of the liquid is small, and therefore, even if the liquid is mixed into the electrolytic solution after the electrolytic cell provided in the laminate, the liquid does not affect the electrolysis itself.

From the practical viewpoint, it is preferable to use a liquid having a surface tension of 24mN/m to 80mN/m, such as ethanol, ethylene glycol, or water. Particularly, water or an aqueous solution obtained by dissolving sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate, or the like in water to be alkaline is preferable. In addition, these liquids may contain a surfactant to adjust the surface tension. By containing the surfactant, the adhesiveness between the separator and the electrode for electrolysis, or between the porous metal plate or the metal plate (power feeder) and the electrode for electrolysis changes, and the workability can be adjusted. The surfactant is not particularly limited, and any of an ionic surfactant and a nonionic surfactant can be used.

The electrode for electrolysis in embodiment 1 is not particularly limited, and the ratio measured by the following method (2) is preferably 90% or more, more preferably 92% or more, and further more preferably 95% or more, from the viewpoint of obtaining good workability and good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode (power feeder), and an electrode (power feeder) to which no catalyst is applied, and from the viewpoint of facilitating handling in a large size (for example, a size of 1.5m × 2.5 m). The upper limit is 100%.

[ method (2) ]

An ion exchange membrane (170mm square) and an electrode sample (130mm square) were laminated in this order. The laminate was placed on a curved surface of a polyethylene tube (outer diameter 280mm) so that the electrode sample in the laminate was outside at a temperature of 23. + -. 2 ℃ and a relative humidity of 30. + -. 5%, the laminate and the tube were sufficiently impregnated with pure water to remove excess water adhering to the surface of the laminate and the tube, and after 1 minute, the percentage (%) of the area of the portion where the ion-exchange membrane (170mm square) and the electrode sample were in close contact with each other was measured.

The electrode for electrolysis in embodiment 1 is not particularly limited, and the ratio measured by the following method (3) is preferably 75% or more, more preferably 80% or more, and further more preferably 90% or more, from the viewpoint of obtaining good workability, good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode (power feeder), and an electrode (power feeder) not coated with a catalyst, and being capable of being suitably rolled up and folded well, and further facilitating handling in a large size (for example, a size of 1.5m × 2.5 m). The upper limit is 100%.

[ method (3) ]

An ion exchange membrane (170mm square) and an electrode sample (130mm square) were laminated in this order. The laminate was placed on a curved surface of a polyethylene tube (outer diameter: 145mm) at a temperature of 23. + -. 2 ℃ and a relative humidity of 30. + -. 5% so that the electrode sample in the laminate was outside, the laminate and the tube were sufficiently impregnated with pure water to remove excess water adhering to the surface of the laminate and the tube, and after 1 minute, the percentage (%) of the area of the portion where the ion-exchange membrane (170mm square) and the electrode sample were in close contact with each other was measured.

The electrode for electrolysis in embodiment 1 is not particularly limited, but is preferably a porous structure having an open pore ratio or a void ratio of 5 to 90% or less, from the viewpoints of obtaining good workability, having good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode (power feeder), and an electrode (power feeder) to which no catalyst is applied, and preventing retention of gas generated during electrolysis. The aperture ratio is more preferably 10 to 80% or less, and still more preferably 20 to 75%.

The open porosity is a ratio of open pores per unit volume. The aperture portion is also calculated by considering the difference in opening to the order of submicron, or only the opening visible to the eye.

Specifically, the open porosity a can be calculated by the following equation by calculating the volume V from the gauge thickness, width, and length values of the electrode and further actually measuring the weight W.

A＝(1－(W/(V×ρ))×100

ρ is the density (g/cm) of the material of the electrode³). For example 8.908g/cm in the case of nickel³4.506g/cm in the case of titanium³. The aperture ratio can be suitably adjusted by the following method: if the metal is punched, changing the area of punching metal in each unit area; if the metal plate net is the metal plate net, changing the values of SW (short diameter), LW (long diameter) and feeding; if the metal fiber is a net, changing the wire diameter and the mesh number of the metal fiber; if electroforming, changing the pattern of the photoresist used; if the non-woven fabric is used, the diameter and the fiber density of the metal fibers are changed; if the metal is foamed, changing a mold for forming the gap; and so on.

The electrode for electrolysis in embodiment 1 has a value measured by the following method (a) of preferably 40mm or less, more preferably 29mm or less, further preferably 10mm or less, and further more preferably 6.5mm or less, from the viewpoint of workability.

[ method (A) ]

Winding and fixing a sample of a laminate obtained by laminating an ion exchange membrane and the electrode for electrolysis on a curved surface of a core material made of vinyl chloride and having an outer diameter of 32mm at a temperature of 23 + -2 ℃ and a relative humidity of 30 + -5%, standing for 6 hours, separating the electrode for electrolysis, and mounting the electrode for electrolysisOn a horizontal plate, the height L in the vertical direction of both ends of the electrode for electrolysis was measured₁And L₂The average value of these values was defined as the measured value.

With respect to the electrode for electrolysis in embodiment 1, the electrode for electrolysis is made to have a size of 50mm × 50mm, and has a temperature of 24 ℃, a relative humidity of 32%, a piston velocity of 0.2cm/s and a ventilation amount of 0.4cc/cm²The aeration resistance (hereinafter also referred to as "aeration resistance 1") in the case of/s (hereinafter also referred to as "measurement condition 1") is preferably 24kPa · s/m or less. The large ventilation resistance means that air is difficult to flow, and means a state of high density. In this state, products generated by electrolysis remain in the electrode, and the reaction substrate is hard to diffuse into the electrode, so that the electrolytic performance (voltage, etc.) tends to deteriorate. In addition, the concentration on the film surface tends to increase. Specifically, the caustic concentration tends to increase on the cathode surface, and the saline water supply property tends to decrease on the anode surface. As a result, the product is accumulated at the interface between the separator and the electrode at a high concentration, and thus the separator tends to be damaged, and the voltage on the cathode surface tends to increase, the film tends to be damaged, and the film tends to be damaged on the anode surface.

In order to prevent these problems, it is preferable to set the ventilation resistance to 24kPa · s/m or less.

From the same points as above, it is more preferably less than 0.19kPa · s/m, still more preferably 0.15kPa · s/m or less, and still more preferably 0.07kPa · s/m or less.

When the gas flow resistance is greater than or equal to a certain value, in the case of the cathode, NaOH generated at the electrode tends to remain at the interface between the electrolysis electrode and the separator and to become high in concentration; in the case of the anode, the salt water supplying property is lowered, the salt water concentration tends to be low, and from the viewpoint of preventing damage to the separator which may occur due to such retention, it is preferably less than 0.19kPa · s/m, more preferably 0.15kPa · s/m or less, and still more preferably 0.07kPa · s/m or less.

On the other hand, when the air flow resistance is low, the area of the electrode is reduced, and therefore, the electrolysis area tends to be reduced, and the electrolysis performance (voltage, etc.) tends to be deteriorated. When the air flow resistance is zero, the power feeder functions as an electrode because no electrode for electrolysis is provided, and the electrolysis performance (voltage, etc.) tends to be significantly deteriorated. From this point of view, the lower limit of the ventilation resistance 1 is not particularly limited, but is preferably greater than 0kPa · s/m, more preferably 0.0001kPa · s/m or more, and still more preferably 0.001kPa · s/m or more.

In addition, in view of the measurement method, it is likely that sufficient measurement accuracy cannot be obtained when the ventilation resistance 1 is 0.07kPa · s/m or less. From this viewpoint, the electrode for electrolysis having an air flow resistance 1 of 0.07kPa · s/m or less can also be evaluated by the air flow resistance (hereinafter also referred to as "air flow resistance 2") according to the following measurement method (hereinafter also referred to as "measurement condition 2"). That is, the aeration resistance 2 is the value obtained by making the size of the electrode for electrolysis 50mm X50 mm, the temperature at 24 ℃, the relative humidity at 32%, the piston velocity at 2cm/s and the aeration amount at 4cc/cm²Ventilation resistance in the case of/s.

The above-described ventilation resistances 1 and 2 can be set to the above-described range by appropriately adjusting, for example, the aperture ratio, the thickness of the electrode, and the like, which will be described later. More specifically, for example, if the thickness is the same, the ventilation resistances 1 and 2 tend to decrease when the opening ratio is increased, and the ventilation resistances 1 and 2 tend to increase when the opening ratio is decreased.

In the electrolysis electrode according to embodiment 1, as described above, the force applied to the separator or the power feeding member per unit mass and unit area is preferably less than 1.5N/mg cm²。

As described above, the electrolysis electrode in embodiment 1 is in contact with the separator or the power feeder (for example, the original anode or cathode in the electrolytic cell) with a suitable adhesive force, and thus a laminate with the separator or the power feeder can be formed. That is, since the separator or the power feeder and the electrode for electrolysis do not need to be firmly bonded by a complicated method such as thermocompression bonding, and the laminate can be formed by bonding even with a relatively weak force such as surface tension from moisture that may be contained in the separator such as an ion exchange membrane or a microporous membrane, the laminate can be easily formed regardless of the scale. Further, since such a laminate can exhibit excellent electrolytic performance, the laminate obtained by the production method of embodiment 1 is suitable for electrolytic use, and can be particularly preferably used for a member of an electrolytic cell or a renewal use of the member.

One embodiment of the electrode for electrolysis will be described below.

The electrolysis electrode preferably includes an electrolysis electrode substrate and a catalyst layer.

The catalyst layer may be composed of a plurality of layers as described below, or may have a single-layer structure.

As shown in fig. 10, the electrolysis electrode 101 includes an electrolysis electrode base 10 and a pair of first layers 20 covering both surfaces of the electrolysis electrode base 10.

The first layer 20 preferably covers the entire electrolytic electrode substrate 10. This makes it easy to improve the catalytic activity and durability of the electrode for electrolysis. The first layer 20 may be laminated on only one surface of the electrode base material for electrolysis 10.

In addition, as shown in fig. 10, the surface of the first layer 20 may be coated with the second layer 30. The second layer 30 preferably covers the entirety of the first layer 20. The second layer 30 may be laminated on only one surface of the first layer 20.

(electrode base for electrolysis)

The electrode base material for electrolysis 10 is not particularly limited, and for example, a valve metal represented by nickel, a nickel alloy, stainless steel, titanium, or the like can be used, and at least one element selected from nickel (Ni) and titanium (Ti) is preferably contained.

When stainless steel is used in a high-concentration alkaline aqueous solution, considering that iron and chromium are eluted out and the conductivity of stainless steel is about 1/10 of nickel, a substrate containing nickel (Ni) is preferable as an electrode substrate for electrolysis.

When the electrode base material for electrolysis 10 is used in a chlorine generating atmosphere in a high-concentration saline solution near saturation, the material is preferably titanium having high corrosion resistance.

The shape of the electrode base material for electrolysis 10 is not particularly limited, and may be selected as appropriate according to the purpose. As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used. Among them, a punched metal or a metal expanded metal is preferable. Electroforming is a technique of combining photolithography and electroplating to form a metal thin film having a precise pattern. In this method, a pattern is formed on a substrate using a photoresist, and a portion not protected by the photoresist is plated to obtain a metal thin film.

The shape of the electrode base material for electrolysis has an appropriate specification depending on the distance between the anode and the cathode in the electrolytic cell. Although not particularly limited, in the case where the anode and the cathode have a limited distance, a metal mesh or a punched metal shape may be used, and in the case of a so-called zero-pitch electrolytic cell in which an ion exchange membrane and an electrode are in contact with each other, a woven mesh, a wire mesh, a foamed metal, a metal nonwoven fabric, a metal mesh, a punched metal, a metal porous foil, or the like, which is formed by weaving fine wires, may be used.

Examples of the electrode base material 10 for electrolysis include a porous metal foil, a wire mesh, a metal nonwoven fabric, a punched metal, a metal lath, and a foamed metal.

The sheet material before being processed into a punched metal or a metal lath is preferably a sheet material formed by rolling, an electrolytic foil, or the like. The electrolytic foil is preferably further subjected to plating treatment using the same elements as the base material as a post-treatment to form irregularities on one or both surfaces.

The thickness of the electrode base material for electrolysis 10 is preferably 300 μm or less, more preferably 205 μm or less, further preferably 155 μm or less, further preferably 135 μm or less, further preferably 125 μm or less, further preferably 120 μm or less, further preferably 100 μm or less, and further preferably 50 μm or less from the viewpoint of workability and economy, as described above. The lower limit is not particularly limited, but is, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

In the electrode base material for electrolysis, it is preferable to relax the residual stress at the time of processing by annealing the electrode base material for electrolysis in an oxidizing atmosphere. In addition, on the surface of the electrode base material for electrolysis, in order to improve adhesion with the catalyst layer coated on the surface, it is preferable to form irregularities by a steel grid, alumina powder, or the like, and then increase the surface area by acid treatment. Alternatively, the surface area is increased by preferably performing plating treatment using the same element as the base material.

In order to make the first layer 20 adhere to the surface of the electrode base material for electrolysis 10, the electrode base material for electrolysis 10 is preferably subjected to a treatment for increasing the surface area. Examples of the treatment for increasing the surface area include blasting using a cut wire, a steel grid, an alumina grid, or the like, acid treatment using sulfuric acid or hydrochloric acid, plating using the same element as the base material, and the like. The arithmetic average surface roughness (Ra) of the surface of the substrate is not particularly limited, but is preferably 0.05 to 50 μm, more preferably 0.1 to 10 μm, and still more preferably 0.1 to 8 μm.

Next, the case of using the electrolysis electrode as the anode for salt electrolysis will be described.

(first layer)

In fig. 10, the first layer 20 as the catalyst layer contains at least one oxide of ruthenium oxide, iridium oxide, and titanium oxide. Examples of the ruthenium oxide include RuO₂And the like. IrO may be mentioned as an iridium oxide₂And the like. The titanium oxide includes TiO₂And the like. The first layer 20 preferably contains two oxides of ruthenium oxide and titanium oxide, or three oxides of ruthenium oxide, iridium oxide, and titanium oxide. This makes the first layer 20 a more stable layer, and further improves the adhesion to the second layer 30.

When the first layer 20 contains both ruthenium oxide and titanium oxide, the amount of titanium oxide contained in the first layer 20 is preferably 1 to 9 mol, and more preferably 1 to 4 mol, based on 1 mol of ruthenium oxide contained in the first layer 20. When the composition ratio of the two oxides is in this range, the electrolytic electrode 101 exhibits excellent durability.

When the first layer 20 contains three oxides, i.e., ruthenium oxide, iridium oxide, and titanium oxide, the iridium oxide contained in the first layer 20 is preferably 0.2 to 3 mol, and more preferably 0.3 to 2.5 mol, based on 1 mol of ruthenium oxide contained in the first layer 20. In addition, the titanium oxide contained in the first layer 20 is preferably 0.3 to 8 mol, and more preferably 1 to 7 mol, based on 1 mol of ruthenium oxide contained in the first layer 20. When the composition ratio of the 3 oxides is in this range, the electrolysis electrode 101 exhibits excellent durability.

In the case where the first layer 20 contains at least two oxides selected from ruthenium oxide, iridium oxide, and titanium oxide, these oxides preferably form a solid solution. By forming an oxide solid solution, the electrode 101 for electrolysis exhibits excellent durability.

In addition to the above composition, as long as at least one oxide of ruthenium oxide, iridium oxide, and titanium oxide is contained, various compositions of the substance can be used. For example, an oxide coating containing ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, or the like, which is called DSA (registered trademark), may also be used as the first layer 20.

The first layer 20 need not be a single layer, but may comprise a plurality of layers. For example, the first layer 20 may contain a layer containing three oxides and a layer containing two oxides. The thickness of the first layer 20 is preferably 0.05 to 10 μm, and more preferably 0.1 to 8 μm.

(second layer)

The second layer 30 preferably comprises ruthenium and titanium. This can further reduce the chlorine overvoltage immediately after the electrolysis.

The second layer 30 preferably comprises palladium oxide, a solid solution of palladium oxide and platinum, or an alloy of palladium and platinum. This can further reduce the chlorine overvoltage immediately after the electrolysis.

When the second layer 30 is thick, the period in which the electrolytic performance can be maintained is long, but from the viewpoint of economy, the thickness is preferably 0.05 to 3 μm.

Next, the case of using the electrolysis electrode as the cathode for salt electrolysis will be described.

(first layer)

Examples of the component of the first layer 20 of the catalyst layer include metals such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of these metals.

With or without at least one of a platinum group metal, a platinum group metal oxide, a platinum group metal hydroxide, an alloy comprising a platinum group metal.

In the case of containing at least one of platinum group metal, platinum group metal oxide, platinum group metal hydroxide, and platinum group metal-containing alloy, the platinum group metal, platinum group metal oxide, platinum group metal hydroxide, and platinum group metal-containing alloy preferably contains at least one platinum group metal of platinum, palladium, rhodium, ruthenium, and iridium.

As the platinum group metal, platinum is preferably contained.

As the platinum group metal oxide, ruthenium oxide is preferably contained.

As the platinum group metal hydroxide, ruthenium hydroxide is preferably contained.

As the platinum group metal alloy, an alloy containing platinum and nickel, iron, cobalt is preferable.

Further, if necessary, an oxide or hydroxide of a lanthanoid element is preferably contained as the second component. Thus, the electrolysis electrode 101 exhibits excellent durability.

As the oxide or hydroxide of lanthanoid, at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium is preferably contained.

Further, if necessary, an oxide or hydroxide of a transition metal is preferably contained as the third component.

By adding the third component, the electrode 101 for electrolysis exhibits more excellent durability, and the electrolysis voltage can be reduced.

Examples of preferred combinations include alloys of only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium + platinum, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead, ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + ruthenium + platinum, and nickel + platinum, and platinum.

When the catalyst does not contain platinum group metals, platinum group metal oxides, platinum group metal hydroxides, or alloys containing platinum group metals, the main component of the catalyst is preferably nickel.

Preferably at least one of nickel metal, oxide, hydroxide.

As the second component, a transition metal may be added. The second component to be added preferably contains at least one element selected from titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper, and carbon.

Preferred combinations include nickel + tin, nickel + titanium, nickel + molybdenum, nickel + cobalt, and the like.

An intermediate layer may be provided between the first layer 20 and the electrode substrate for electrolysis 10 as needed. By providing the intermediate layer, the durability of the electrode 101 for electrolysis can be improved.

The intermediate layer preferably has affinity for both the first layer 20 and the electrolytic electrode substrate 10. As the intermediate layer, nickel oxide, platinum group metal oxide, platinum group metal hydroxide are preferable. The intermediate layer may be formed by applying a solution containing the intermediate layer-forming component and firing the solution, or the surface oxide layer may be formed by subjecting the substrate to a heat treatment at a temperature of 300 to 600 ℃ in an air atmosphere. Further, it can be formed by a known method such as a thermal spraying method, an ion plating method, or the like.

(second layer)

Examples of the component of the second layer 30 of the catalyst layer include metals such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of these metals.

With or without at least one of a platinum group metal, a platinum group metal oxide, a platinum group metal hydroxide, an alloy comprising a platinum group metal. Examples of preferable combinations of elements included in the second layer include the combinations mentioned in the first layer. The combination of the first layer and the second layer may be a combination of the same composition but different composition ratios, or a combination of different compositions.

The thickness of the catalyst layer is preferably 0.01 to 20 μm in total of the thickness of the catalyst layer and the intermediate layer. When the particle diameter is 0.01 μm or more, the catalyst can sufficiently exhibit its function as a catalyst. When the thickness is 20 μm or less, the amount of the catalyst layer is reduced, and a strong catalyst layer can be formed. More preferably 0.05 μm to 15 μm. More preferably 0.1 to 10 μm. More preferably 0.2 to 8 μm.

The thickness of the electrolysis electrode, i.e., the total thickness of the electrode base material for electrolysis and the catalyst layer, is preferably 315 μm or less, more preferably 220 μm or less, further preferably 170 μm or less, further preferably 150 μm or less, further preferably 145 μm or less, further preferably 140 μm or less, further preferably 138 μm or less, and further preferably 135 μm or less, from the viewpoint of the operability of the electrolysis electrode.

When the particle diameter is 315 μm or less, good workability can be obtained.

From the same viewpoint as above, it is preferably 130 μm or less, more preferably less than 130 μm, still more preferably 115 μm or less, and still more preferably 65 μm or less.

The lower limit is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, and still more preferably 20 μm or more from the practical viewpoint. The thickness of the electrode can be determined by measuring with a digital display thickness gauge (Mitutoyo, ltd., minimum display 0.001 mm). The thickness of the electrode base material for electrolysis can be measured in the same manner as the thickness of the electrode for electrolysis. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrode base material for electrolysis from the thickness of the electrode for electrolysis.

(method of manufacturing electrode for electrolysis)

Next, one embodiment of the method for manufacturing the electrolysis electrode 101 will be described in detail.

In embodiment 1, the first layer 20, preferably the second layer 30, is formed on the electrode base material for electrolysis by a method such as baking (thermal decomposition) of a coating film in an oxygen atmosphere, ion plating, or thermal spraying, whereby the electrode 101 for electrolysis can be produced.

Such a method of manufacturing an electrolysis electrode can realize high productivity of the electrolysis electrode 101. Specifically, the catalyst layer is formed on the electrode base material for electrolysis by a coating step of coating a coating liquid containing a catalyst, a drying step of drying the coating liquid, and a thermal decomposition step of thermally decomposing. The thermal decomposition here means that a metal salt as a precursor is heated to be decomposed into a metal or a metal oxide and a gaseous substance. Although the decomposition products vary depending on the kind of metal used, the kind of salt, the atmosphere in which thermal decomposition is performed, and the like, many metals tend to form oxides under an oxidizing atmosphere. In the industrial production process of electrodes, thermal decomposition is generally carried out in air, and metal oxides or metal hydroxides are formed in many cases.

(formation of the first layer of the anode)

(coating Process)

The first layer 20 is obtained by applying a solution (first coating liquid) in which a metal salt of at least one of ruthenium, iridium, and titanium is dissolved to an electrode base material for electrolysis, and then thermally decomposing (firing) the solution in the presence of oxygen. The contents of ruthenium, iridium, and titanium in the first coating liquid are substantially equal to those of the first layer 20.

The metal salt may be any of hydrochloride, nitrate, sulfate, metal alkoxide, and other salts. The solvent of the first coating liquid may be selected according to the kind of the metal salt, and alcohols such as water and butanol may be used. As the solvent, water or a mixed solvent of water and an alcohol is preferable. The total metal concentration in the first coating liquid in which the metal salt is dissolved is not particularly limited, and is preferably in the range of 10 to 150g/L in view of compatibility with the thickness of the coating film formed by one-time coating.

As a method of applying the first coating liquid to the electrode base material for electrolysis 10, there are used an immersion method of immersing the electrode base material for electrolysis 10 in the first coating liquid, a method of applying the first coating liquid with bristles, a roll method using a sponge-like roll in which the first coating liquid is immersed, an electrostatic coating method of spraying and atomizing the electrode base material for electrolysis 10 and the first coating liquid with opposite charges, and the like. Among them, a roll method or an electrostatic coating method excellent in industrial productivity is preferable.

(drying step, thermal decomposition step)

The first coating liquid is applied to the electrode base material 10 for electrolysis, dried at a temperature of 10 to 90 ℃, and thermally decomposed in a firing furnace heated to 350 to 650 ℃. During the drying and thermal decomposition, the pre-firing may be performed at 100 to 350 ℃ as required. The drying, pre-firing and thermal decomposition temperatures may be appropriately selected depending on the composition of the first coating liquid or the kind of solvent. The time per thermal decomposition is preferably long, and from the viewpoint of productivity of the electrode, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

The above cycle of coating, drying, and thermal decomposition is repeated to form the coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed, if necessary, the first layer 20 can be further stabilized by heating after firing for a long time.

(formation of second layer)

The second layer 30 is formed as needed, and is obtained by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating solution) onto the first layer 20 and then thermally decomposing the applied solution in the presence of oxygen.

(formation of the first layer of the cathode by thermal decomposition)

(coating Process)

The first layer 20 is obtained by applying a solution (first coating liquid) in which metal salts of various combinations are dissolved to an electrode base material for electrolysis, and then thermally decomposing (firing) the applied solution in the presence of oxygen. The content of the metal in the first coating liquid is substantially equal to that of the first layer 20 after firing.

The metal salt may be any of hydrochloride, nitrate, sulfate, metal alkoxide, and other salts. The solvent of the first coating liquid may be selected according to the kind of the metal salt, and alcohols such as water and butanol may be used. As the solvent, water or a mixed solvent of water and an alcohol is preferable. The total metal concentration in the first coating liquid in which the metal salt is dissolved is not particularly limited, and is preferably in the range of 10 to 150g/L in view of compatibility with the thickness of the coating film formed by one-time coating.

As a method of applying the first coating liquid to the electrode base material for electrolysis 10, there are used an immersion method of immersing the electrode base material for electrolysis 10 in the first coating liquid, a method of applying the first coating liquid with bristles, a roll method using a sponge-like roll in which the first coating liquid is immersed, an electrostatic coating method of spraying and atomizing the electrode base material for electrolysis 10 and the first coating liquid with opposite charges, and the like. Among them, a roll method or an electrostatic coating method excellent in industrial productivity is preferable.

(drying step, thermal decomposition step)

The first coating liquid is applied to the electrode base material 10 for electrolysis, dried at a temperature of 10 to 90 ℃, and thermally decomposed in a firing furnace heated to 350 to 650 ℃. During the drying and thermal decomposition, the pre-firing may be performed at 100 to 350 ℃ as required. The drying, pre-firing and thermal decomposition temperatures may be appropriately selected depending on the composition of the first coating liquid or the kind of solvent. The time per thermal decomposition is preferably long, and from the viewpoint of productivity of the electrode, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

The above cycle of coating, drying, and thermal decomposition is repeated to form the coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed, if necessary, the first layer 20 can be further stabilized by heating after firing for a long time.

(formation of intermediate layer)

The intermediate layer is formed as needed, and is obtained by applying a solution (second coating solution) containing a palladium compound or a platinum compound to a substrate and then thermally decomposing the applied solution in the presence of oxygen. Alternatively, the nickel oxide intermediate layer may be formed on the surface of the substrate by heating only the substrate without applying the solution.

(formation of the first layer of the cathode by ion plating)

The first layer 20 may also be formed using ion plating.

As an example, a method of fixing the substrate in the chamber and irradiating the metallic ruthenium target with an electron beam may be mentioned. The evaporated ruthenium metal particles are positively charged in the plasma in the chamber and accumulate on the negatively charged substrate. The plasma atmosphere was argon and oxygen, and ruthenium was deposited on the substrate as ruthenium oxide.

(formation of the first layer by means of a plated cathode)

The first layer 20 may be formed by plating.

For example, when electroplating is performed in an electrolytic solution containing nickel and tin using a base material as a cathode, an alloy plating layer of nickel and tin can be formed.

(formation of the first layer by means of a thermally sprayed cathode)

The first layer 20 may also be formed using a thermal spray process.

For example, nickel oxide particles may be plasma sprayed onto the substrate to form a catalyst layer in which metallic nickel and nickel oxide are mixed.

(formation of the second layer of the cathode)

The second layer 30 is formed as needed, and is obtained by applying a solution containing an iridium compound, a palladium compound, and a platinum compound or a solution containing a ruthenium compound to the first layer 20, and then thermally decomposing the applied solution in the presence of oxygen.

The electrode for electrolysis may be used in combination with a separator such as an ion exchange membrane or a microporous membrane.

Therefore, the membrane-integrated electrode can be used as a membrane-integrated electrode, and the replacement work of the cathode and the anode when the electrode is replaced is not necessary, so that the work efficiency is greatly improved.

Further, by using an integrated electrode with a separator such as an ion exchange membrane or a microporous membrane, the electrolytic performance can be made equal to that in the case of a new product or improved.

As the separator used in embodiment 1, an ion exchange membrane is mentioned as a suitable separator.

The ion exchange membrane will be described in detail below.

[ ion exchange Membrane ]

The ion exchange membrane has a membrane main body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and a coating layer provided on at least one surface of the membrane main body. In addition, the coating layer comprises inorganic particles and a binder, and the specific surface area of the coating layer is 0.1 to 10m ²(ii) in terms of/g. In the ion exchange membrane having such a structure, the gas generated during electrolysis has little influence on the electrolytic performance, and stable electrolytic performance can be exhibited.

The above-mentioned membrane of perfluorocarbon polymer having an ion exchange group introduced thereinto is a membrane having an ion exchange group (-SO) derived from a sulfo group₃A sulfonic acid layer of the group represented, hereinafter also referred to as "sulfonic acid group"), and an ion exchange group (-CO) having a group derived from a carboxyl group₂-the group represented, hereinafter also referred to as "carboxylic acid group") of the carboxylic acid layer. From the viewpoint of strength and dimensional stability, it is preferable to further include a reinforcing core material.

The inorganic particles and the binder are described in detail below in the column of the description of the coating layer.

FIG. 11 is a schematic sectional view showing one embodiment of an ion exchange membrane.

The ion exchange membrane 1 has a membrane main body 1a containing a hydrocarbon-based polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane main body 1 a.

In the ion exchange membrane 1, the membrane main body 1a has an ion exchange group (-SO) having a sulfo group₃ ^-A sulfonic acid layer 3 of a group represented by the formula, hereinafter also referred to as "sulfonic acid group"), and an ion exchange group (-CO) derived from a carboxyl group ₂ ^-The group represented, hereinafter also referred to as "carboxylic acid group") of the carboxylic acid layer 2 is reinforced in strength and strength by reinforcing the core material 4Dimensional stability. The ion exchange membrane 1 is provided with a sulfonic acid layer 3 and a carboxylic acid layer 2, and is therefore suitable as a cation exchange membrane.

The ion exchange membrane may have only one of the sulfonic acid layer and the carboxylic acid layer. The ion exchange membrane does not necessarily need to be reinforced by the reinforcing core material, and the arrangement state of the reinforcing core material is not limited to the example of fig. 11.

(film body)

First, the membrane main body 1a constituting the ion exchange membrane 1 will be explained.

The membrane main body 1a has a function of selectively transmitting cations, and may be made of any suitable material, as long as it contains a hydrocarbon-based polymer or fluorine-containing polymer having an ion exchange group.

The hydrocarbon-based polymer or fluorine-containing polymer having an ion exchange group in the membrane main body 1a can be obtained, for example, from a hydrocarbon-based polymer or fluorine-containing polymer having an ion exchange group precursor which can be converted into an ion exchange group by hydrolysis or the like.

Specifically, the membrane main body 1a can be obtained by preparing a precursor of the membrane main body 1a using a polymer (hereinafter, referred to as "fluorine-containing polymer (a)" as the case may be) whose main chain is composed of a fluorinated hydrocarbon, which has a group convertible into an ion exchange group by hydrolysis or the like (ion exchange group precursor) as a pendant side chain, and which is melt-processable, and then converting the ion exchange group precursor into an ion exchange group.

The fluorine-containing polymer (a) can be produced, for example, by copolymerizing at least one monomer selected from the following group 1 with at least one monomer selected from the following group 2 and/or the following group 3. The copolymer can also be produced by homopolymerization of 1 monomer selected from any one of the following groups 1, 2 and 3.

Examples of the monomer of group 1 include fluorinated vinyl compounds. Examples of the vinyl fluoride compound include ethylene fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ether. In particular, when an ion exchange membrane is used as the membrane for alkali electrolysis, the vinyl fluoride compound is preferably a perfluoromonomer, preferably a perfluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, and perfluoroalkyl vinyl ether.

Examples of the group 2 monomer include vinyl compounds having a functional group that can be converted into a carboxylic acid type ion exchange group (carboxylic acid group). Examples of the vinyl compound having a functional group which can be converted into a carboxylic acid group include CF₂＝CF(OCF₂CYF)_s-O(CZF)_tA monomer represented by-COOR (s is an integer of 0 to 2, t is an integer of 1 to 12, and Y and Z are each independently F or CF) ₃And R represents a lower alkyl group. The lower alkyl group is, for example, an alkyl group having 1 to 3 carbon atoms).

Among these, CF is preferred₂＝CF(OCF₂CYF)_n-O(CF₂)_m-COOR. Wherein n represents an integer of 0 to 2, m represents an integer of 1 to 4, and Y represents F or CF₃R represents CH₃、C₂H₅Or C₃H₇。

When an ion exchange membrane is used as the cation exchange membrane for alkali electrolysis, it is preferable to use at least a perfluoro compound as a monomer, but since the alkyl group of the ester group (see R above) is removed from the polymer at the time of hydrolysis, the alkyl group (R) may not be a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

Among the monomers of group 2, the monomers represented by the following are more preferable.

CF₂＝CFOCF₂-CF(CF₃)OCF₂COOCH₃、

CF₂＝CFOCF₂CF(CF₃)O(CF₂)₂COOCH₃、

CF₂＝CF[OCF₂-CF(CF₃)]₂O(CF₂)₂COOCH₃、

CF₂＝CFOCF₂CF(CF₃)O(CF₂)₃COOCH₃、

CF₂＝CFO(CF₂)₂COOCH₃、

CF₂＝CFO(CF₂)₃COOCH₃。

Examples of the monomer of group 3 include vinyl compounds having a functional group that can be converted into a sulfone type ion exchange group (sulfonic acid group). As the vinyl compound having a functional group capable of being converted into a sulfonic acid group, for example, CF is preferable₂＝CFO-X-CF₂-SO₂And F (wherein X represents a perfluoroalkylene group). Specific examples thereof include monomers shown below.

CF₂＝CFOCF₂CF₂SO₂F、

CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂F、

CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂CF₂SO₂F、

CF₂＝CF(CF₂)₂SO₂F、

CF₂＝CFO[CF₂CF(CF₃)O]₂CF₂CF₂SO₂F、

CF₂＝CFOCF₂CF(CF₂OCF₃)OCF₂CF₂SO₂F。

Among these, CF is more preferable₂＝CFOCF₂CF(CF₃)OCF₂CF₂CF₂SO₂F and CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂F。

Copolymers obtained from these monomers can be produced by polymerization methods developed for homopolymerization and copolymerization of fluorinated ethylene, particularly by general polymerization methods used for tetrafluoroethylene. For example, in the nonaqueous method, polymerization can be carried out at a temperature of 0 to 200 ℃ and a pressure of 0.1 to 20MPa in the presence of a radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound using an inert solvent such as perfluorocarbon or chlorofluorocarbon.

In the copolymerization, the kind and the ratio of the combination of the monomers are not particularly limited, and are selected and determined according to the kind and the amount of the functional group to be imparted to the resulting fluorine-containing polymer. For example, in the case of forming a fluorine-containing polymer containing only carboxylic acid groups, at least one monomer selected from the above-mentioned groups 1 and 2 may be copolymerized. In the case of forming a fluorine-containing polymer containing only sulfonic acid groups, at least one monomer selected from the above-mentioned group 1 and group 3 monomers may be copolymerized. In the case of forming a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group, at least one monomer selected from the group consisting of the monomers of the above-mentioned groups 1, 2 and 3 may be copolymerized. In this case, the intended fluoropolymer can also be obtained by polymerizing the copolymer composed of the groups 1 and 2 and the copolymer composed of the groups 1 and 3, respectively, and then mixing them. The mixing ratio of the monomers is not particularly limited, and when the amount of the functional group per unit polymer is increased, the ratio of the monomers selected from the above-mentioned groups 2 and 3 may be increased.

The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0mg equivalent/g, more preferably 0.6 to 1.5mg equivalent/g. Here, the total ion exchange capacity is an equivalent of an exchange group per unit mass of the dried resin, and can be measured by neutralization titration or the like.

The membrane main body 1a of the ion exchange membrane 1 is formed by laminating a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group. By forming the membrane main body 1a having such a layer structure, the selective permeability of cations such as sodium ions can be further improved.

When the ion exchange membrane 1 is disposed in an electrolytic cell, it is generally disposed such that the sulfonic acid layer 3 is located on the anode side of the electrolytic cell and the carboxylic acid layer 2 is located on the cathode side of the electrolytic cell.

The sulfonic acid layer 3 is preferably made of a material having low electric resistance, and is preferably thicker than the carboxylic acid layer 2 in terms of film strength. The film thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times that of the carboxylic acid layer 2.

The carboxylic acid layer 2 preferably has high anion exclusivity even if the film thickness is thin. The anion exclusivity as used herein refers to a property of preventing anions from entering or passing through the ion exchange membrane 1. In order to improve the anion-excluding property, it is effective to dispose a carboxylic acid layer or the like having a small ion exchange capacity with respect to the sulfonic acid layer.

As the fluorine-containing polymer used for the sulfonic acid layer 3, for example, CF is used₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂Polymers obtained with F as a monomer of group 3 are suitable.

As the fluorine-containing polymer for the carboxylic acid layer 2, for example, CF is used₂＝CFOCF₂CF(CF₂)O(CF₂)₂COOCH₃Polymers obtained as monomers of group 2 are suitable.

(coating layer)

The ion exchange membrane has a coating layer on at least one face of the membrane main body. As shown in fig. 11, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of a membrane main body 1a, respectively.

The coating layer comprises inorganic particles and a binder.

The average particle diameter of the inorganic particles is more preferably 0.90 μm or more. When the average particle diameter of the inorganic particles is 0.90 μm or more, not only adhesion to gas but also durability against impurities is remarkably improved. That is, particularly significant effects are obtained by increasing the average particle diameter of the inorganic particles and satisfying the above-described values of the specific surface area. In order to satisfy such an average particle diameter and specific surface area, inorganic particles having an irregular shape are preferable. Inorganic particles obtained by melting or inorganic particles obtained by pulverizing raw ore can be used. Preferably, inorganic particles obtained by pulverizing raw ore can be suitably used.

The inorganic particles may have an average particle diameter of 2 μm or less. When the average particle diameter of the inorganic particles is 2 μm or less, damage of the film due to the inorganic particles can be prevented. The average particle diameter of the inorganic particles is more preferably 0.90 to 1.2 μm.

Here, the average particle diameter can be measured by a particle size distribution meter ("SALD 2200", Shimadzu Corp.).

The shape of the inorganic particles is preferably irregular. The resistance to impurities can be further improved. In addition, the particle size distribution of the inorganic particles is preferably broad.

The inorganic particles preferably contain at least one inorganic substance selected from the group consisting of an oxide of a group IV element of the periodic table, a nitride of a group IV element of the periodic table, and a carbide of a group IV element of the periodic table. Particles of zirconia are more preferable from the viewpoint of durability.

The inorganic particles are preferably inorganic particles produced by pulverizing raw ores of the inorganic particles, or spherical particles obtained by melting and refining raw ores of the inorganic particles and having uniform particle diameters.

The raw ore grinding method is not particularly limited, and examples thereof include a ball mill, a bead mill, a colloid mill, a cone mill, a disc mill, an edger, a flour mill, a hammer mill, a pellet mill, a VSI mill, a Wiley mill, a roll mill, and a jet mill. It is preferable to wash the powder after pulverization, and in this case, it is preferable to carry out acid treatment. This can reduce impurities such as iron adhering to the surface of the inorganic particles.

The coating layer preferably comprises a binder. The binder is a component for forming a coating layer by holding inorganic particles on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer in terms of resistance against the electrolytic solution or the product generated by electrolysis.

The binder is more preferably a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group, from the viewpoint of resistance against an electrolytic solution or a product resulting from electrolysis, and adhesion to the surface of the ion exchange membrane. When a coating layer is provided on a layer (sulfonic acid layer) containing a fluorine-containing polymer having a sulfonic acid group, a fluorine-containing polymer having a sulfonic acid group is preferably used as a binder for the coating layer. When a coating layer is provided on a layer (carboxylic acid layer) containing a fluoropolymer having carboxylic acid groups, a fluoropolymer having carboxylic acid groups is preferably used as the binder for the coating layer.

In the coating layer, the content of the inorganic particles is preferably 40 to 90 mass%, more preferably 50 to 90 mass%. The content of the binder is preferably 10 to 60% by mass, and more preferably 10 to 50% by mass.

The distribution density of the coating layer in the ion exchange membrane is preferably 1cm per unit ²Is 0.05-2 mg. When the ion exchange membrane has irregularities on the surface, the distribution density of the coating layer is preferably 1cm²Is 0.5-2 mg.

The method for forming the coating layer is not particularly limited, and a known method can be used. For example, a method in which inorganic particles are dispersed in a solution containing a binder and the obtained coating liquid is applied by spraying or the like can be mentioned.

(strengthening core material)

The ion exchange membrane preferably has a reinforcing core material disposed inside the membrane main body.

The reinforcing core material is a member for reinforcing the strength and dimensional stability of the ion exchange membrane. By disposing the reinforcing core material inside the membrane main body, the expansion and contraction of the ion exchange membrane can be controlled particularly within a desired range. The ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long period of time.

The structure of the reinforcing core material is not particularly limited, and for example, a yarn called a reinforcing yarn may be spun to form the reinforcing core material. The reinforcing filaments referred to herein are members constituting a reinforcing core material, and refer to filaments capable of imparting desired dimensional stability and mechanical strength to an ion-exchange membrane and stably existing in the ion-exchange membrane. By using a reinforcing core material obtained by spinning the reinforcing yarn, more excellent dimensional stability and mechanical strength can be imparted to the ion-exchange membrane.

The material of the reinforcing core material and the reinforcing filaments used for the reinforcing core material is not particularly limited, but is preferably a material having resistance to acids, alkalis, and the like, and is preferably a fiber made of a fluorine-containing polymer because heat resistance and chemical resistance are required for a long period of time.

Examples of the fluorine-containing polymer for reinforcing the core material include Polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer, chlorotrifluoroethylene-ethylene copolymer, and vinylidene fluoride Polymer (PVDF). Among these, fibers made of polytetrafluoroethylene are particularly preferably used from the viewpoint of heat resistance and chemical resistance.

The diameter of the reinforcing yarn for reinforcing the core material is not particularly limited, but is preferably 20 to 300 deniers, and more preferably 50 to 250 deniers. The weaving density (the number of beating-up threads per unit length) is preferably 5 to 50 threads/inch. The form of the reinforcing core material is not particularly limited, and for example, woven fabric, nonwoven fabric, woven fabric, and the like are used, and the form of woven fabric is preferable. The thickness of the woven fabric is preferably 30 to 250 μm, more preferably 30 to 150 μm.

The woven or knitted fabric may be monofilament, multifilament, or yarn or slit yarn thereof, and various weaving methods such as plain weaving, leno weaving, knitting, pin-hole weaving, and crepe-wale weaving may be used.

The weave and arrangement of the reinforcing core material in the membrane main body are not particularly limited, and the reinforcing core material may be suitably arranged in consideration of the size and shape of the ion exchange membrane, the desired physical properties of the ion exchange membrane, the use environment, and the like.

For example, the reinforcing core material may be arranged along a predetermined one direction of the film main body, but from the viewpoint of dimensional stability, it is preferable to arrange the reinforcing core material along a predetermined first direction and arrange the other reinforcing core material along a second direction substantially perpendicular to the first direction. By arranging a plurality of reinforcing core members in a substantially straight line inside the longitudinal film body of the film body, more excellent dimensional stability and mechanical strength can be imparted in multiple directions. For example, it is preferable to weave a reinforcing core material (warp) arranged in the longitudinal direction and a reinforcing core material (weft) arranged in the transverse direction into the surface of the film main body. From the viewpoints of dimensional stability, mechanical strength, and ease of production, more preferred are: a plain weave in which warp threads and weft threads are alternately floated and sunk and are knitted by beating; 2 warps are twisted and woven with wefts at the same time; a square plain weave is woven by beating up the same number of weft yarns for 2 or more warp yarns which are respectively arranged in a pulling and aligning way; and so on.

In particular, it is preferable that the reinforcing core material is disposed in both the MD Direction (Machine Direction) and the TD Direction (Transverse Direction) of the ion exchange membrane. That is, it is preferable to perform plain weaving in the MD direction and the TD direction.

Here, the MD direction refers to a direction (flow direction) in which the membrane main body and various core materials (for example, a reinforced core material, a reinforced yarn, a sacrificial yarn described later, and the like) are transported in a process of producing an ion exchange membrane described later, and the TD direction refers to a direction substantially perpendicular to the MD direction. The yarns woven in the MD are referred to as MD yarns, and the yarns woven in the TD are referred to as TD yarns. Generally, many ion exchange membranes used for electrolysis are rectangular, and the longitudinal direction is the MD direction and the width direction is the TD direction. By weaving a reinforcing core material as MD yarns and a reinforcing core material as TD yarns, more excellent dimensional stability and mechanical strength can be provided in multiple directions.

The arrangement interval of the reinforcing core material is not particularly limited, and an appropriate arrangement can be appropriately set in consideration of the desired physical properties of the ion exchange membrane, the use environment, and the like.

The aperture ratio of the reinforcing core material is not particularly limited, but is preferably 30% or more, and more preferably 50% or more and 90% or less. The aperture ratio is preferably 30% or more in view of the electrochemical properties of the ion-exchange membrane, and preferably 90% or less in view of the mechanical strength of the ion-exchange membrane.

The aperture ratio of the reinforcing core material is a ratio (B/a) of a total area (B) of surfaces through which an ion or the like (electrolyte and a cation (for example, sodium ion) contained therein) can pass in an area (a) of any one surface of the film body. The total area (B) of the surface through which the ion or other substance can pass is the total area of the region of the ion-exchange membrane, which is not divided by the reinforcing core material or the like included in the ion-exchange membrane, such as cations or an electrolyte.

Fig. 12 is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion-exchange membrane.

Fig. 12 is an enlarged view of a part of the ion exchange membrane, and only the arrangement of the reinforcing core members 21a and 21b in this region is illustrated, and the other members are not illustrated.

The total area (B) of the region in which the ion or other substance can pass in the area (a) of the region can be obtained by subtracting the total area (C) of the reinforcing core materials from the area (a) of the region surrounded by the reinforcing core materials 21a arranged in the longitudinal direction and the reinforcing core materials 21B arranged in the lateral direction (including the area of the reinforcing core materials). That is, the aperture ratio can be obtained by the following formula (I).

(B)/(a) ═ ((a) - (C))/(a) … (I)

In the reinforcing core material, a flat yarn or a highly oriented monofilament yarn containing PTFE is particularly preferable from the viewpoint of chemical resistance and heat resistance. Specifically, more preferred are: cutting a high-strength porous sheet made of PTFE into a band-shaped flat wire; or a reinforcing core material having a thickness in the range of 50 to 100 [ mu ] m, which is a plain weave having a weaving density of 10 to 50 threads/inch and using highly oriented monofilaments made of PTFE, and which has a denier of 50 to 300. The opening ratio of the ion-exchange membrane including the reinforced core material is more preferably 60% or more.

Examples of the shape of the reinforcing yarn include a round yarn and a ribbon yarn.

(communicating hole)

The ion exchange membrane preferably has communication holes in the interior of the membrane main body.

The communicating hole is a hole that can serve as a flow path for ions and an electrolyte solution generated during electrolysis. The communicating hole is a tubular hole formed in the film body, and is formed by elution of a sacrificial core material (or a sacrificial filament) described later. The shape, diameter, and the like of the communication hole can be controlled by selecting the shape and diameter of the sacrificial core material (sacrificial wire).

By forming the communicating holes in the ion exchange membrane, the mobility of the electrolytic solution can be ensured during electrolysis. The shape of the communicating hole is not particularly limited, and may be the shape of a sacrificial core material for forming the communicating hole according to a production method described later.

The communication hole is preferably formed so as to alternately pass through the anode side (sulfonic acid layer side) and the cathode side (carboxylic acid layer side) of the reinforcing core material. With this configuration, even in a portion where the through holes are formed on the cathode side of the reinforcing core material, ions (for example, sodium ions) transported by the electrolyte solution filling the through holes can flow to the cathode side of the reinforcing core material. As a result, the flow of cations is not obstructed, and the electrical resistance of the ion exchange membrane can be further reduced.

The communication holes may be formed only in a predetermined one direction of the membrane main body constituting the ion exchange membrane, but are preferably formed in both the longitudinal direction and the transverse direction of the membrane main body from the viewpoint of exerting more stable electrolytic performance.

[ method for producing ion exchange Membrane ]

A preferred method for producing an ion exchange membrane includes the following steps (1) to (6).

(1) The process comprises the following steps: a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor which can be an ion exchange group by hydrolysis.

(2) The process comprises the following steps: and if necessary, weaving at least a plurality of reinforcing core materials and sacrificial filaments having a property of dissolving in an acid or an alkali and forming communication holes, thereby obtaining a reinforcing material in which the sacrificial filaments are arranged between adjacent reinforcing core materials.

(3) The process comprises the following steps: and a step of forming a film of the fluorine-containing polymer having an ion exchange group or an ion exchange group precursor which can be an ion exchange group by hydrolysis.

(4) The process comprises the following steps: and a step of embedding the reinforcing material in the film as necessary to obtain a film body in which the reinforcing material is arranged.

(5) The process comprises the following steps: and (4) hydrolyzing the film body obtained in step (4) (hydrolysis step).

(6) The process comprises the following steps: and (5) providing a coating layer on the film body obtained in the step (5) (coating step).

The respective steps will be described in detail below.

(1) The process comprises the following steps: process for producing fluorine-containing polymer

In the step (1), the fluorine-containing polymer is produced by using the monomers of the raw materials described in the above-mentioned groups 1 to 3. In order to control the ion exchange capacity of the fluorine-containing polymer, the mixing ratio of the monomers of the raw materials may be adjusted in the production of the fluorine-containing polymer forming each layer.

(2) The process comprises the following steps: process for producing reinforcing material

The reinforcing material is a woven fabric or the like obtained by weaving reinforcing yarns. The reinforced core material is formed by embedding a reinforcing material in a film. When an ion exchange membrane having interconnected pores is produced, sacrificial filaments are also woven into the reinforcing material together. The amount of the sacrificial filaments mixed is preferably 10 to 80% by mass, more preferably 30 to 70% by mass of the entire reinforcing material. The shift of the reinforcing core material can also be prevented by weaving the sacrificial thread.

The sacrificial filaments have solubility in the film production process or the electrolytic environment, and rayon, polyethylene terephthalate (PET), cellulose, polyamide, or the like is used. Further, polyvinyl alcohol having a thickness of 20 to 50 deniers and composed of monofilament or multifilament is also preferable.

In the step (2), the arrangement of the reinforcing core material and the sacrificial wire is adjusted to control the aperture ratio, the arrangement of the communicating holes, and the like.

(3) The process comprises the following steps: film formation step

In the step (3), the fluoropolymer obtained in the step (1) is formed into a film by an extruder. The film may have a single-layer structure, may have a 2-layer structure of the sulfonic acid layer and the carboxylic acid layer as described above, or may have a multilayer structure of 3 or more layers.

Examples of the method for forming a film include the following methods.

A method for forming a film by separating a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group.

A method for producing a composite film by coextrusion of a fluoropolymer having a carboxylic acid group and a fluoropolymer having a sulfonic acid group.

The number of the films may be two or more. In addition, coextrusion of different types of films is preferable because it contributes to improvement in the interfacial adhesive strength.

(4) The process comprises the following steps: process for obtaining film body

In the step (4), the reinforcing material obtained in the step (2) is embedded in the film obtained in the step (3), thereby obtaining a film body in which the reinforcing material is present.

Preferred methods for forming the film body include: (i) a method in which a fluorine-containing polymer having a carboxylic acid group precursor (for example, a carboxylic acid ester group) on the cathode side (hereinafter, a layer formed of the polymer is referred to as a first layer) and a fluorine-containing polymer having a sulfonic acid group precursor (for example, a sulfonyl fluoride functional group) (hereinafter, a layer formed of the polymer is referred to as a second layer) are formed into a film by a coextrusion method, a heat source and a vacuum source are used as necessary, a reinforcing material and a second layer/first layer composite film are laminated in this order on a flat plate or a cylinder having a large number of pores on the surface, through a heat-resistant release paper having air permeability, and air between the layers is removed by reducing the pressure at a temperature at which the polymers are melted to integrate the layers; (ii) a method in which a fluorine-containing polymer having a sulfonic acid group precursor (third layer) is separately formed into a film separately from the second/first composite film, and the film is laminated in this order on a flat plate or a cylinder having a large number of fine pores on the surface thereof via a heat-resistant release paper having air permeability, using a heat source and a vacuum source as necessary, and the composite film composed of the third layer, the reinforcing core material, and the second/first composite film is integrated by removing air between the layers by reducing the pressure at a temperature at which the polymers are melted.

Here, co-extrusion of the first and second layers helps to improve the interfacial bond strength.

In addition, the method of integration under reduced pressure has a feature that the thickness of the third layer on the reinforcing material is increased as compared with the pressure pressing method. Further, since the reinforcing material is fixed to the inner surface of the membrane main body, the reinforcing material has a property of being able to sufficiently maintain the mechanical strength of the ion exchange membrane.

The conversion pattern of lamination described here is an example, and an appropriate lamination pattern (for example, a combination of layers or the like) may be appropriately selected in consideration of the layer structure, physical properties, and the like of a desired film body, and then coextrusion may be performed.

In order to further improve the electrical performance of the ion exchange membrane, a fourth layer made of a fluorine-containing polymer having both a carboxylic acid group precursor and a sulfonic acid group precursor may be interposed between the first layer and the second layer, or a fourth layer made of a fluorine-containing polymer having both a carboxylic acid group precursor and a sulfonic acid group precursor may be used instead of the second layer.

The fourth layer may be formed by separately producing a fluorine-containing polymer having a carboxylic acid group precursor and a fluorine-containing polymer having a sulfonic acid group precursor and mixing them, or by using a copolymer of a monomer having a carboxylic acid group precursor and a monomer having a sulfonic acid group precursor.

In the case where the fourth layer is an ion exchange membrane, the first layer and the fourth layer may be formed as a co-extruded film, and the third layer and the second layer may be separately formed into films and laminated by the above-described method; the 3 layers of the first layer/fourth layer/second layer may be formed into a film by coextrusion at a time.

In this case, the flow direction of the extruded film is the MD direction. In this way, a membrane body including a fluorine-containing polymer having an ion exchange group can be formed on the reinforcing material.

The ion exchange membrane preferably has a protruding portion, i.e., a convex portion, made of a fluoropolymer having a sulfonic acid group on the surface side made of the sulfonic acid layer. The method for forming such a convex portion is not particularly limited, and a known method for forming a convex portion on a resin surface can be employed. Specifically, for example, a method of embossing the surface of the film body may be mentioned. For example, when the composite film and the reinforcing material are integrated, the convex portion can be formed by using a release paper which is embossed in advance. When the projections are formed by embossing, the height and arrangement density of the projections can be controlled by controlling the embossing shape (the shape of the release paper) to be transferred.

(5) Hydrolysis step

In the step (5), the following steps are performed: hydrolyzing the membrane main body obtained in the step (4) to convert the ion exchange group precursor into an ion exchange group (hydrolysis step).

In the step (5), the sacrificial filaments included in the film body may be dissolved and removed with an acid or an alkali, thereby forming the dissolution holes in the film body. The sacrificial filaments may remain in the communicating holes and not be completely dissolved and removed. In addition, when the ion exchange membrane is used for electrolysis, the sacrificial filaments remaining in the communicating holes can be dissolved and removed by the electrolyte solution.

The sacrificial filaments have solubility to acids or alkalis in the process of producing the ion exchange membrane or in the electrolytic environment, and the sacrificial filaments are dissolved out to form communicating pores at the portions.

(5) The step (4) may be performed by immersing the film body obtained in the step (4) in a hydrolysis solution containing an acid or an alkali. As the hydrolysis solution, for example, a mixed solution containing KOH and DMSO (dimethyl sulfoxide) may be used.

The mixed solution preferably contains 2.5 to 4.0N KOH and 25 to 35 mass% DMSO.

The hydrolysis temperature is preferably 70 to 100 ℃. The higher the temperature, the more the apparent thickness can be further increased. More preferably 75 to 100 ℃.

The hydrolysis time is preferably 10 to 120 minutes. The longer the time, the more the apparent thickness can be further increased. More preferably 20 to 120 minutes.

Here, the step of forming the communicating hole by dissolving out the sacrificial thread will be described in more detail.

Fig. 13 (a) and (B) are schematic views for explaining a method of forming the communicating holes of the ion-exchange membrane.

In fig. 13 (a) and (B), only the reinforcing wires 52, the sacrificial wires 504a, and the communication holes 504 formed by the sacrificial wires 504a are illustrated, and other members such as the film main body are not illustrated.

First, reinforcing filaments 52 constituting a reinforcing core material in an ion exchange membrane and sacrificial filaments 504a for forming communicating holes 504 in the ion exchange membrane are woven to produce a reinforcing material. In the step (5), the sacrificial filaments 504a are eluted to form the communication holes 504.

According to the above method, the method of weaving the reinforcing filaments 52 and the sacrificial filaments 504a can be adjusted depending on the arrangement of the reinforcing core material and the communication holes in the membrane main body of the ion exchange membrane, and thus, the method is simple.

Fig. 13 (a) illustrates a plain-weave reinforcing material in which reinforcing filaments 52 and sacrificial filaments 504a are woven into a paper surface in both the longitudinal direction and the transverse direction, but the arrangement of the reinforcing filaments 52 and the sacrificial filaments 504a in the reinforcing material may be changed as necessary.

(6) Coating step

In the step (6), a coating liquid containing inorganic particles obtained by pulverizing or melting raw ore and a binder is prepared, and the coating liquid is applied to the surface of the ion-exchange membrane obtained in the step (5) and dried, whereby a coating layer can be formed.

As the binder, a binder obtained as follows is preferable: a fluorine-containing polymer having an ion exchange group precursor is hydrolyzed with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersed in hydrochloric acid to replace the counter ion of the ion exchange group with H + (for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). This is preferable because it is easily dissolved in water or ethanol described later.

The binder was dissolved in a mixed solution of water and ethanol. The preferable volume ratio of water to ethanol is 10: 1 to 1: 10, more preferably 5: 1 to 1: 5, and still more preferably 2: 1 to 1: 2. The inorganic particles are dispersed in the thus-obtained solution by a ball mill to obtain a coating liquid. In this case, the average particle diameter of the particles can be adjusted by adjusting the time and the rotational speed at which the dispersion is performed. The preferred mixing amounts of the inorganic particles and the binder are as described above.

The concentration of the inorganic particles and the binder in the coating liquid is not particularly limited, and a dilute coating liquid is preferably prepared. Thereby being capable of being uniformly applied to the surface of the ion exchange membrane.

In addition, when the inorganic particles are dispersed, a surfactant may be added to the dispersion liquid. As the surfactant, nonionic surfactants are preferred, and examples thereof include HS-210, NS-210, P-210, E-212 and the like manufactured by Nichisu oil Co.

The obtained coating liquid was applied to the surface of the ion exchange membrane by spray coating or roll coating, thereby obtaining an ion exchange membrane.

[ microporous film ]

As the separator used in embodiment 1, a microporous membrane is also mentioned as a suitable separator.

As described above, the microporous membrane is not particularly limited as long as it can be formed into a laminate with an electrode for electrolysis, and various microporous membranes can be used.

The porosity of the microporous membrane is not particularly limited, and may be, for example, 20 to 90, preferably 30 to 85. The porosity can be calculated by the following equation, for example.

Porosity ═ 1- (weight of film in dry state)/(weight calculated from volume calculated from thickness, width, and length of film and density of film material)) × 100

The average pore diameter of the microporous membrane is not particularly limited, and may be, for example, 0.01 to 10 μm, preferably 0.05 to 5 μm. The average pore diameter is, for example, observed by cutting the membrane perpendicularly to the thickness direction and observing the cross section by FE-SEM. The average pore diameter can be determined by measuring about 100 points of the diameter of the observed pore and averaging the measured diameters.

The thickness of the microporous membrane is not particularly limited, and may be, for example, 10 to 1000. mu.m, preferably 50 to 600. mu.m. The thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo corporation).

Specific examples of the microporous membrane include those described in Zirfon Perl UTP 500 (also referred to as Zirfon membrane in embodiment 1) manufactured by Agfa, pamphlet of International publication No. 2013-183584, pamphlet of International publication No. 2016-203701, and the like.

In embodiment 1, the separator preferably comprises a 1 st ion exchange resin layer and a 2 nd ion exchange resin layer having an EW (ion exchange equivalent weight) different from that of the 1 st ion exchange resin layer. In addition, the separator preferably includes a 1 st ion exchange resin layer and a 2 nd ion exchange resin layer having a functional group different from that of the 1 st ion exchange resin layer. The ion exchange equivalent can be adjusted by the functional group to be introduced, and the functional group to be introduced is as described above.

The reason why the laminate obtained by the laminate manufacturing jig of embodiment 1 exhibits excellent electrolytic performance is presumed as follows.

In the case where the separator and the electrode for electrolysis are strongly bonded by a method such as thermocompression bonding as in the prior art, the electrode for electrolysis is physically bonded in a state of being sunk into the separator. The adhesive portion interferes with the movement of sodium ions in the film, and the voltage is greatly increased.

On the other hand, as in embodiment 1, by bringing the electrolysis electrode into contact with the separator or the power feeding body with an appropriate adhesive force, the movement of sodium ions in the membrane, which has been a problem in the prior art, is not prevented.

Thus, when the separator or the current-supplying member is brought into contact with the electrolysis electrode with an appropriate adhesive force, excellent electrolysis performance can be exhibited even though the separator or the current-supplying member and the electrolysis electrode are integrated.

[ method for producing a laminate ]

A method for manufacturing a laminate according to embodiment 1 is a method for obtaining a laminate in which an electrode roll around which a long-sized electrode for electrolysis is wound and a separator roll around which a long-sized separator is wound are used to obtain a laminate of an electrode for electrolysis and a separator, which are wound out from the electrode roll and the separator roll, respectively, and the method includes a step of winding out the wound electrode for electrolysis and separator while fixing relative positions of the electrode roll and the separator roll, and a step of supplying moisture to the electrode for electrolysis wound out from the electrode roll. With the above-described configuration, the method for producing a laminate according to embodiment 1 can produce a laminate that can improve the work efficiency in the case of replacing the electrodes and the separators in the electrolytic cell. That is, even when a relatively large-sized member is required to fit an electrolytic cell of a practical commercial size (for example, 1.5m long and 3m wide), a desired layered body can be easily obtained by a simple operation of arranging and fixing the electrode roll and the separator roll at desired positions, and integrating the electrode for electrolysis and the separator by the moisture supplied from the water retention means while feeding the electrodes for electrolysis and the separator from the respective rolls.

The method for manufacturing a laminate according to embodiment 1 is preferably performed using the jig for manufacturing a laminate according to embodiment 1.

[ roll body ]

The laminate according to embodiment 1 may be a roll. By reducing the size of the laminate by winding it, the workability can be further improved.

[ electrolytic tank ]

The laminate of embodiment 1 is incorporated in an electrolytic cell.

An embodiment of the electrolytic cell will be described in detail below by taking a case of performing salt electrolysis using an ion exchange membrane as a diaphragm as an example.

The electrolytic cell of embodiment 1 is not limited to the case of performing salt electrolysis, and may be used for water electrolysis, fuel cells, and the like.

[ electrolytic cell ]

Fig. 14 is a sectional view of the electrolysis cell 50.

The electrolysis unit 50 includes an anode chamber 60, a cathode chamber 70, a partition wall 80 provided between the anode chamber 60 and the cathode chamber 70, an anode 11 provided in the anode chamber 60, and a cathode 21 provided in the cathode chamber 70.

The cathode chamber may be provided with a reverse current absorbing member 18 provided therein as necessary, and the reverse current absorbing member 18 may include a base member 18a and a reverse current absorbing layer 18b formed on the base member 18 a.

The anode 11 and the cathode 21 belonging to one electrolysis unit 50 are electrically connected to each other. In other words, the electrolysis unit 50 includes the following cathode structure.

The cathode structure 90 includes a cathode chamber 70, a cathode 21 provided in the cathode chamber 70, and a reverse current absorber 18 provided in the cathode chamber 70, the reverse current absorber 18 includes a base 18a and a reverse current absorbing layer 18b formed on the base 18a as shown in fig. 18, and the cathode 21 is electrically connected to the reverse current absorbing layer 18 b.

The cathode chamber 70 further includes a current collector 23, a support 24 for supporting the current collector, and a metal elastic body 22.

The metal elastic body 22 is disposed between the current collector 23 and the cathode 21.

The support 24 is provided between the current collector 23 and the partition 80.

The current collector 23 is electrically connected to the cathode 21 through the metal elastic body 22.

The partition 80 is electrically connected to the current collector 23 via the support 24. Therefore, the partition wall 80, the support 24, the current collector 23, the metal elastic body 22, and the cathode 21 are electrically connected.

The cathode 21 and the reverse current absorbing layer 18b are electrically connected.

The cathode 21 and the reverse current absorbing layer 18b may be directly connected to each other, or may be indirectly connected to each other through a current collector, a support, a metal elastic body, a partition wall, or the like.

The entire surface of the cathode 21 is preferably coated with a catalyst layer for reduction reaction.

In addition, the electrical connection method may be as follows: the partition wall 80 is directly attached to the support 24, the support 24 is directly attached to the current collector 23, the current collector 23 is directly attached to the metal elastic body 22, and the cathode 21 is laminated on the metal elastic body 22. As a method of directly attaching these components to each other, welding and the like are given. The reverse current absorber 18, the cathode 21, and the current collector 23 may be collectively referred to as a cathode structure 90.

FIG. 15 is a sectional view of 2 adjacent electrolysis cells 50 in the electrolysis vessel 4.

Fig. 16 shows the electrolytic cell 4.

FIG. 17 shows a process for assembling the electrolytic cell 4.

As shown in fig. 15, the electrolysis unit 50, the cation exchange membrane 51, and the electrolysis unit 50 are arranged in series in this order.

An ion exchange membrane 51 as a diaphragm is disposed between the anode chamber of one electrolysis cell 50 and the cathode chamber of the other electrolysis cell 50 of the adjacent 2 electrolysis cells in the electrolysis cell 4.

That is, the anode chamber 60 of the electrolysis cell 50 and the cathode chamber 70 of the electrolysis cell 50 adjacent thereto are separated by the cation exchange membrane 51.

As shown in fig. 16, the electrolytic cell 4 is composed of a plurality of electrolytic cells 50 connected in series via an ion exchange membrane 51.

That is, the electrolytic cell 4 is a bipolar type electrolytic cell including a plurality of electrolytic cells 50 arranged in series and an ion exchange membrane 51 arranged between the adjacent electrolytic cells 50.

As shown in fig. 17, the electrolytic cell 4 is assembled by arranging a plurality of electrolytic cells 50 in series via an ion exchange membrane 51 and connecting them by a pressurizer 5.

The electrolytic cell 4 has an anode terminal 7 and a cathode terminal 6 connected to a power supply.

The anode 11 of the electrolysis cell 50 positioned at the endmost part among the plurality of electrolysis cells 50 connected in series in the electrolysis vessel 4 is electrically connected to the anode terminal 7.

Among the plurality of electrolysis cells 50 connected in series in the electrolytic cell 4, the cathode 21 of the electrolysis cell located at the end opposite to the anode terminal 7 is electrically connected to the cathode terminal 6.

The current during electrolysis flows from the anode terminal 7 side to the cathode terminal 6 via the anode and cathode of each electrolysis cell 50. The electrolytic cell (anode terminal cell) having only the anode chamber and the electrolytic cell (cathode terminal cell) having only the cathode chamber may be disposed at both ends of the connected electrolytic cell 50. In this case, the anode terminal 7 is connected to the anode terminal unit disposed at one end thereof, and the cathode terminal 6 is connected to the cathode terminal unit disposed at the other end thereof.

When brine is electrolyzed, brine is supplied to each anode chamber 60, and pure water or a low-concentration sodium hydroxide aqueous solution is supplied to the cathode chamber 70.

Each liquid is supplied from an electrolyte supply pipe (not shown) to each electrolysis cell 50 via an electrolyte supply hose (not shown).

In addition, the electrolytic solution and the products generated by electrolysis are recovered by an electrolytic solution recovery pipe (not shown in the figure). During electrolysis, sodium ions in the brine move from the anode chamber 60 of one electrolysis cell 50 to the cathode chamber 70 of the adjacent electrolysis cell 50 through the ion exchange membrane 51. Thereby, the current in electrolysis flows in the direction in which the electrolysis cells 50 are connected in series.

That is, an electric current flows from anode chamber 60 to cathode chamber 70 through cation exchange membrane 51.

With the electrolysis of the brine, chlorine gas is generated on the anode 11 side, and sodium hydroxide (solute) and hydrogen gas are generated on the cathode 21 side.

(Anode compartment)

The anode chamber 60 has an anode 11 or an anode power supply 11.

When the electrolysis electrode is inserted into the anode side by inserting the laminate, 11 functions as an anode current carrier.

When the laminate is not inserted, that is, the electrolysis electrode is not inserted on the anode side, 11 functions as an anode. In addition, anode chamber 60 preferably has: an anode side electrolyte supply unit for supplying an electrolyte to the anode chamber 60; a baffle plate disposed above the anode-side electrolyte supply unit and substantially parallel to or inclined with respect to the partition wall 80; and an anode-side gas-liquid separation unit disposed above the baffle plate and configured to separate gas from the electrolyte into which the gas is mixed.

(Anode)

When the electrolysis electrode is not inserted into the anode side, the anode 11 is provided in the frame of the anode chamber 60.

As the anode 11, a metal electrode such as so-called DSA (registered trademark) can be used. DSA refers to an electrode of a titanium substrate whose surface is coated with an oxide containing ruthenium, iridium, and titanium as components.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(Anode power supply body)

When the electrolysis electrode is inserted into the anode side by inserting the laminate, the anode feeder 11 is provided in the frame of the anode chamber 60.

As the anode current collector 11, a metal electrode such as DSA (registered trademark) or the like may be used, or titanium which is not coated with a catalyst may be used. In addition, DSA with a reduced catalyst coating thickness may be used. In addition, a used anode may also be used.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(Anode-side electrolyte supply unit)

The anode side electrolyte supply unit supplies an electrolyte to the anode chamber 60, and is connected to an electrolyte supply pipe.

The anode-side electrolyte supply unit is preferably disposed below the anode chamber 60.

As the anode-side electrolyte supply unit, for example, a tube (dispersion tube) having an opening formed on the surface thereof can be used. The tube is more preferably arranged parallel to the bottom 19 of the electrolysis cell along the surface of the anode 11. This pipe is connected to an electrolyte supply pipe (liquid supply nozzle) for supplying an electrolyte into the electrolysis cell 50. The electrolytic solution supplied from the liquid supply nozzle is transferred into the electrolytic cell 50 through a tube, and is supplied into the anode chamber 60 from an opening provided on the surface of the tube. It is preferable to arrange the tube along the surface of the anode 11 in parallel with the bottom 19 of the electrolytic cell, because the electrolytic solution can be uniformly supplied into the anode chamber 60.

(gas-liquid separator on Anode side)

The gas-liquid separation portion on the anode side is preferably disposed above the baffle plate. In the electrolysis, the anode-side gas-liquid separation section has a function of separating a product gas such as chlorine gas and an electrolytic solution. Unless otherwise specified, the upper direction refers to the upward direction in the electrolytic cell 50 of fig. 14, and the lower direction refers to the downward direction in the electrolytic cell 50 of fig. 14.

When the generated gas generated in the electrolysis unit 50 and the electrolytic solution form a mixed phase (gas-liquid mixed phase) and are discharged to the outside of the system during electrolysis, vibration may occur due to pressure fluctuations inside the electrolysis unit 50, and physical damage to the ion exchange membrane may occur. In order to suppress this phenomenon, the electrolysis cell 50 is preferably provided with an anode-side gas-liquid separation unit for separating gas and liquid. A defoaming plate for defoaming bubbles is preferably provided in the anode-side gas-liquid separation section. When the gas-liquid mixed phase flows through the defoaming plate, bubbles are broken, and the gas-liquid mixed phase can be separated into the electrolyte and the gas. As a result, vibration during electrolysis can be prevented.

(baffle plate)

The baffle plate is preferably disposed above the anode-side electrolyte supply unit and substantially parallel to or inclined with respect to the partition wall 80.

The baffle plate is a separator that controls the flow of the electrolyte in the anode chamber 60.

By providing the baffle plate, the electrolyte (brine, etc.) can be internally circulated in the anode chamber 60, and the concentration thereof can be made uniform.

In order to generate the internal circulation, the baffle plate is preferably arranged so as to separate the space near the anode 11 from the space near the partition wall 80. From this point of view, the baffle plate is preferably provided so as to face the respective surfaces of the anode 11 and the partition wall 80. In the space near the anode partitioned by the baffle plate, the electrolyte concentration (brine concentration) decreases due to the progress of electrolysis, and a generated gas such as chlorine gas is generated. This causes a difference in specific gravity between the gas and liquid in the space near the anode 11 partitioned by the baffle plate and the space near the partition wall 80. By utilizing this difference in specific gravity, the internal circulation of the electrolyte in anode chamber 60 can be promoted, and the concentration distribution of the electrolyte in anode chamber 60 can be made more uniform.

Although not shown in fig. 14, a current collector may be separately provided inside anode chamber 60.

The current collector may be made of the same material or have the same structure as the current collector of the cathode chamber described later. In the anode chamber 60, the anode 11 itself may function as a current collector.

(next door)

The partition 80 is disposed between the anode chamber 60 and the cathode chamber 70.

The partition wall 80 is also referred to as a separator, and divides the anode chamber 60 and the cathode chamber 70.

As the partition wall 80, a material known as a separation plate for electrolysis can be used, and examples thereof include a partition wall in which a plate made of nickel is welded to the cathode side and a plate made of titanium is welded to the anode side.

(cathode chamber)

In the cathode chamber 70, 21 functions as a cathode current-supplying body when the electrolysis electrode constituting the laminate is inserted on the cathode side, and 21 functions as a cathode when the electrolysis electrode is not inserted on the cathode side.

In the case of having a reverse current sink 18, the cathode or cathode current provider 21 is electrically connected to the reverse current sink 18.

In addition, the cathode chamber 70 also preferably includes a cathode electrolyte supply unit and a cathode gas-liquid separation unit, similarly to the anode chamber 60.

Among the parts constituting the cathode chamber 70, the same parts as those constituting the anode chamber 60 are not described.

(cathode)

When the laminate of embodiment 1 is not inserted, that is, when the electrolysis electrode is not inserted to the cathode side, the cathode 21 is provided in the frame of the cathode chamber 70.

The cathode 21 preferably has a nickel substrate and a catalyst layer coated with the nickel substrate. Examples of the component of the catalyst layer on the nickel base material include metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of the metals.

As a method of forming the catalyst layer, plating, alloy plating, dispersion/composite plating, CVD, PVD, thermal decomposition, and spray coating can be cited. These methods may also be combined. The catalyst layer may have a plurality of layers or a plurality of elements as necessary. The cathode 21 may be subjected to a reduction treatment as needed. As the base material of the cathode 21, nickel, a nickel alloy, or a base material obtained by nickel-plating iron or stainless steel may be used.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(cathode power supply body)

In the case where the laminate of embodiment 1 is inserted to insert the electrolysis electrode on the cathode side, the cathode power supply body 21 is provided in the frame of the cathode chamber 70.

The cathode power-supply body 21 may be coated with a catalyst component.

The catalyst component is a component that is originally used as a cathode and remains. Examples of the component of the catalyst layer include metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of the metals.

As a method of forming the catalyst layer, plating, alloy plating, dispersion/composite plating, CVD, PVD, thermal decomposition, and spray coating can be cited. These methods may also be combined. The catalyst layer may have a plurality of layers or a plurality of elements as necessary. In addition, nickel, a nickel alloy, or a material obtained by nickel-plating iron or stainless steel without catalyst coating may be used. As the base material of the cathode element 21, nickel, a nickel alloy, or a base material obtained by nickel-plating iron or stainless steel may be used.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(reverse current absorbing layer)

As the material of the reverse current absorbing layer, a material having an oxidation-reduction potential lower than that of the element for the catalyst layer of the cathode can be selected. Examples thereof include nickel and iron.

(Current collector)

The cathode chamber 70 preferably includes a current collector 23.

This improves the current collecting effect. In embodiment 1, the current collector 23 is preferably a porous plate and is disposed substantially parallel to the surface of the cathode 21.

The current collector 23 is preferably made of a metal having conductivity, such as nickel, iron, copper, silver, or titanium. The current collector 23 may be a mixture, an alloy, or a composite oxide of these metals. The shape of the current collector 23 may be any shape as long as it functions as a current collector, and may be a plate shape or a mesh shape.

(Metal elastomer)

By providing the metal elastic body 22 between the current collector 23 and the cathode 21, the cathodes 21 of the plurality of electrolysis cells 50 connected in series are pressed against the ion exchange membrane 51, and the distance between the anodes 11 and the cathodes 21 is shortened, thereby reducing the voltage applied to the entire plurality of electrolysis cells 50 connected in series.

By reducing the voltage, power consumption can be reduced. Further, when the metal elastic body 22 is provided and the laminate including the electrolysis electrode is provided in the electrolysis unit 50, the electrolysis electrode can be stably maintained at a fixed position by the pressing pressure generated by the metal elastic body 22.

As the metal elastic body 22, a spring member such as a coil spring or a coil, a cushion pad, or the like can be used. As the metal elastic body 22, an appropriate metal elastic body can be suitably used in consideration of stress or the like for pressing the ion exchange membrane 51. The metal elastic body 22 may be provided on the surface of the current collector 23 on the cathode chamber 70 side, or may be provided on the surface of the partition wall on the anode chamber 60 side.

In general, the cathode chamber 70 is divided into two chambers so as to be smaller than the anode chamber 60, and therefore, it is preferable to provide the metal elastic body 22 between the current collector 23 of the cathode chamber 70 and the cathode 21 in terms of the strength of the frame body and the like.

The metal elastic body 23 is preferably made of a metal having conductivity, such as nickel, iron, copper, silver, or titanium.

(support)

The cathode chamber 70 preferably includes a support 24 that electrically connects the current collector 23 and the partition 80. This enables efficient flow of current.

The support 24 is preferably made of a metal having conductivity, such as nickel, iron, copper, silver, or titanium.

The shape of the support 24 may be any shape as long as it can support the current collector 23, and may be a rod, a plate, or a mesh. The support body 24 is, for example, plate-shaped.

The plurality of supports 24 are disposed between the partition 80 and the current collector 23. The plurality of supports 24 are arranged so that their respective surfaces are parallel to each other. The support 24 is disposed substantially perpendicular to the partition 80 and the current collector 23.

(Anode side gasket, cathode side gasket)

The anode gasket 12 is preferably disposed on the surface of a frame constituting the anode chamber 60. The cathode-side gasket 13 is preferably disposed on the surface of the frame constituting the cathode chamber 70. The electrolytic cells 50 are connected to each other so that the ion exchange membrane 51 is sandwiched between the anode-side gasket 12 of one electrolytic cell and the cathode-side gasket 13 of an adjacent electrolytic cell (see fig. 14 and 15).

When a plurality of electrolysis cells 50 are connected in series via the cation exchange membrane 51 by these gaskets, airtightness can be provided to the connection points.

The gasket is a member for sealing between the ion exchange membrane and the electrolytic cell. Specific examples of the gasket include a frame-shaped rubber sheet having an opening formed in the center thereof. The gasket is required to have resistance to corrosive electrolyte, generated gas, and the like and to be usable for a long period of time. Therefore, a vulcanizate or a peroxide crosslinked product of ethylene propylene diene monomer (EPDM rubber), ethylene propylene diene monomer (EPM rubber), or the like is generally used as a gasket in terms of chemical resistance and hardness. Further, a gasket in which a region in contact with a liquid (liquid contact portion) is coated with a fluorine resin such as Polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) may be used as necessary.

The shape of each of these spacers is not particularly limited as long as it has an opening so as not to obstruct the flow of the electrolyte. For example, a frame-shaped gasket is attached with an adhesive or the like along the periphery of each opening of an anode chamber frame constituting the anode chamber 60 or a cathode chamber frame constituting the cathode chamber 70. For example, when 2 electrolysis units 50 are connected to each other via the ion exchange membrane 51 (see fig. 15), the electrolysis units 50 to which gaskets are attached may be fastened via the ion exchange membrane 51. This can prevent the electrolyte solution, alkali metal hydroxide produced by electrolysis, chlorine gas, hydrogen gas, and the like from leaking to the outside of the electrolytic cell 50.

(ion exchange Membrane)

The ion-exchange membrane 51 is as described in the above section of the ion-exchange membrane.

(Water electrolysis)

The electrolytic cell is used for electrolysis of water, and has a structure in which the ion exchange membrane in the electrolytic cell is changed to a microporous membrane. The present invention is different from the above-described electrolytic cell for salt electrolysis in that the raw material to be supplied is water. In the case of other configurations, the electrolytic cell for electrolysis of water may be configured in the same manner as the electrolytic cell for electrolysis of salt.

In the case of salt electrolysis, chlorine gas is generated in the anode chamber, and therefore titanium is used as a material for the anode chamber. Examples thereof include nickel. The anode coating is preferably a catalyst coating for oxygen generation. Examples of the catalyst coating include metals, oxides, and hydroxides of platinum group metals and transition metals. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

(use of the laminate)

As described above, the laminate obtained in embodiment 1 can improve the operation efficiency in the electrode renewal in the electrolytic cell, and can exhibit excellent electrolysis performance even after the renewal. In other words, the laminate according to embodiment 1 can be suitably used as a laminate for exchanging parts of an electrolytic cell. The laminate used in this application is particularly referred to as a "membrane electrode assembly".

(packaging body)

The laminated body obtained by the manufacturing method of embodiment 1 is preferably transported in a state of a package enclosed in a packaging material.

That is, the package body includes a laminate and a packaging material for packaging the laminate. With the above configuration, the package can prevent adhesion and damage of dirt that may occur when the laminated body is transported or the like. When the electrolytic cell is used for exchanging parts, it is particularly preferable to carry the electrolytic cell as a package. The packaging material is not particularly limited, and various known packaging materials can be used. The package can be produced by, but not limited to, a method of packaging the laminate with a clean packaging material and then sealing the package.

< embodiment 2 >

Embodiment 2 of the present invention will be described in detail below.

[ layered body ]

The laminate according to embodiment 2 comprises an electrode for electrolysis and a separator laminated on the surface of the electrode for electrolysis, wherein the separator has an uneven structure on the surface thereof, and the ratio a of the volume of the gap between the electrode for electrolysis and the separator to the unit area of the separator is greater than 0.8 μm and not greater than 200 μm. With the laminate of embodiment 2 thus configured, it is possible to suppress an increase in voltage and a decrease in current efficiency, to exhibit excellent electrolysis performance, to improve the operating efficiency during electrode renewal in an electrolytic cell, and to exhibit excellent electrolysis performance even after the renewal.

In a structure in which an electrode and a separator are integrated by the method described in patent documents 1 and 2, such as the structure described in patent documents, there is a possibility that the voltage may increase or the current efficiency may decrease, and the electrolytic performance may be insufficient. The shape of the separator is not mentioned in this document, and the present inventors have conducted intensive studies on the shape of the separator, and as a result, have obtained the following technical idea: the raw material or product of electrolysis tends to easily remain at the interface between the electrode for electrolysis and the separator, and in the case of the cathode, NaOH generated from the electrode tends to remain at the interface between the electrode for electrolysis and the separator. The present inventors have further conducted extensive studies based on this technical idea, and as a result, have found that by providing a surface of a separator with an uneven structure and setting a ratio a of a gap volume between an electrolysis electrode and the separator to a unit area of the separator within a predetermined range, retention of NaOH at the above-mentioned interface can be suppressed, and as a result, an increase in voltage and a decrease in current efficiency can be suppressed, and electrolysis performance can be improved.

The laminate obtained by the method for producing a laminate according to embodiment 1 preferably has the features of the laminate according to embodiment 2. That is, the laminate of embodiment 2 can be preferably obtained by the method for producing the laminate of embodiment 1. As described above, the electrodes for electrolysis and the separators constituting the laminate of embodiment 2 are the same as those described in embodiment 1 unless otherwise mentioned, and therefore redundant description is omitted.

The interfacial water content w held at the interface of the separator and the electrode for electrolysis is preferably 30g/m²Above 200g/m²Hereinafter, more preferably 54g/m²Above 150g/m²Hereinafter, more preferably 63g/m²Above 120g/m²The following. When the interfacial water content w is in the above range, the retention of NaOH at the above-mentioned interface can be suppressed, and as a result, the increase in voltage and the increase in voltage can be suppressedThe reduction in current efficiency tends to improve the electrolytic performance. The interfacial water content w was determined by the method described later in examples. The interfacial water content w can be adjusted to the above range by adjusting, for example, the surface shape of the separator (specifically, the shape of the irregularities, the height and depth of the irregularities, and the frequency of the irregularities). Similarly, the surface shape of the electrode for electrolysis (more specifically, the shape of the irregularities, the height and depth of the irregularities, the frequency of the irregularities, and the like) can be adjusted to the above-mentioned range. Both the separator and the electrolysis electrode may have a concavo-convex shape. More specifically, if the height of the irregularities in the electrode for electrolysis and/or the separator is increased, the interfacial water content w tends to increase, and the higher the frequency of the irregularities, the higher the interfacial water content w tends to increase.

[ undulations ]

The electrode for electrolysis in embodiment 2 preferably has 1 or a plurality of undulations on the surface facing the separator, and the undulations satisfy the following conditions (i) to (iii).

0.04≦S_a/S_all≦0.55…(i)

0.010mm²≦S_ave≦10.0mm²…(ii)

1<(h+t)/t≦10…(iii)

(in the above-mentioned (i), S_aThe total area S of the undulation portion in an observation image obtained by observing the facing surface with an optical microscope_allShowing the area of the facing surface in the observation image,

in the above (ii), S_aveRepresents an average area of the undulation portion in the observation image,

in the above (iii), h represents the height of the undulation portion, and t represents the thickness of the electrolysis electrode. )

In the structures in which the electrodes for electrolysis and the separators are integrated as described in patent documents 1 and 2, there is a possibility that the voltage increases or the current efficiency decreases, and the electrolysis performance is insufficient. The document does not mention the electrode shape, and the present inventors have conducted intensive studies on the electrode shape, and as a result, have obtained the following technical idea: the raw material or product of electrolysis tends to easily remain at the interface between the electrode for electrolysis and the separator, and in the case of the cathode, NaOH generated at the electrode tends to remain at the interface between the electrode for electrolysis and the separator. The present inventors have further conducted extensive studies based on this technical idea, and as a result, have found that when an electrode for electrolysis has a specific undulation portion on the surface facing the separator and the undulation portion satisfies the conditions (i) to (iii), retention of NaOH at the above-mentioned interface can be suppressed, and as a result, an increase in voltage and a decrease in current efficiency can be suppressed, and electrolysis performance can be improved. That is, according to the laminate of embodiment 2, it is possible to suppress an increase in voltage and a decrease in current efficiency, and excellent electrolytic performance can be exhibited.

(Condition (i))

With respect to S_a/S_allThe content of the metal oxide is preferably 0.04 to 0.55 from the viewpoint of ensuring desired electrolytic performance, and more preferably 0.05 to 0.55, even more preferably 0.05 to 0.50, and still more preferably 0.125 to 0.50 from the viewpoint of further improving electrolytic performance. S_a/S_allFor example, the above range can be adjusted by adopting a preferable production method described later, and the measurement method thereof includes the method described in the examples described later.

(Condition (ii))

With respect to S_ave0.010mm in order to ensure desired electrolytic performance²Above 10.0mm²Hereinafter, from the viewpoint of further improving the electrolytic performance, it is preferably 0.07mm²Above 10.0mm²Less than, more preferably 0.07mm²Above 4.3mm²Preferably 0.10mm or less²Above 4.3mm²Below, most preferably 0.20mm²Above 4.3mm²The following. S_aveFor example, the above-mentioned range can be adjusted by adopting a preferable production method described later, and the measurement method thereof includes the method described in the examples described later.

(Condition (iii))

The ratio (h + t)/t is preferably greater than 1 and 10 or less in order to ensure desired electrolytic performance, and more preferably 1.05 to 7.0, more preferably 1.1 to 6.0, and even more preferably 2.0 to 6.0 in order to further improve electrolytic performance. The (h + t)/t can be adjusted to the above range by adopting a preferable production method described later, for example, and the measurement method thereof can be the method described in the examples described later. Here, the electrode for electrolysis in the present embodiment may include an electrode substrate for electrolysis and a catalyst layer (catalyst coating layer) as described below, and in the examples described below, the electrode substrate for electrolysis after the uneven processing is subjected to the catalyst coating and the produced electrode for electrolysis is measured for h.

From the same viewpoint as above, the value of h/t is preferably greater than 0 and 9 or less, more preferably 0.05 to 6.0, even more preferably 0.1 to 5.0, and even more preferably 1.0 to 5.0. The value of h can be appropriately adjusted depending on the value of t so as to satisfy condition (iii), and is typically preferably greater than 0 μm and 2700 μm or less, more preferably 0.5 μm to 1000 μm, even more preferably 5 μm to 500 μm, and even more preferably 10 μm to 300 μm.

In embodiment 2, the undulation means a concave portion or a convex portion, and it means a portion satisfying the conditions (i) to (iii) when subjected to the measurement described in the following examples. Here, the concave portion refers to a portion protruding in a direction opposite to the diaphragm, and the convex portion refers to a portion protruding in a direction toward the diaphragm. In embodiment 2, when the electrolysis electrode has a plurality of undulations, the electrolysis electrode may have only a plurality of undulations as recesses, only a plurality of undulations as projections, or both undulations as recesses and projections.

The undulation portion in embodiment 2 is formed on the surface of the electrolysis electrode facing the separator, but the same concave and/or convex portions as the undulation portion may be formed on the surface of the electrolysis electrode other than the facing surface.

In embodiment 2, a value M (═ S) obtained by multiplying the values of (i) to (iii) is obtained_a/S_all×S_aveX (h + t)/t) is a value representing the balance of conditions (i) to (iii), and the M value is preferably 0.04 to 15, more preferably 0.05 to 10, and further preferably 0.05 to 5, from the viewpoint of suppressing the voltage increase.

Fig. 19 to 21 are schematic cross-sectional views showing an example of an electrolysis electrode in embodiment 2.

In the electrode 101A for electrolysis shown in fig. 19, a plurality of undulation portions (projections) 102A are arranged at a specific interval. Fig. 10 described in embodiment 1 corresponds to an enlarged portion of the portion surrounded by the broken line P shown in fig. 19.

In this example, a flat portion 103A is disposed between adjacent undulating portions (convex portions) 102A. In this example, the undulation portions are convex portions, but in the electrolysis electrode in embodiment 2, the undulation portions may be concave portions. In this example, the height and width of each convex portion are the same, but the height and width of each convex portion may be different in the electrolysis electrode in embodiment 2. Here, the electrolysis electrode 101A shown in fig. 22 is a plan perspective view of the electrolysis electrode 101A shown in fig. 19.

In the electrolysis electrode 101B shown in fig. 20, the undulation portions (projections) 102B are arranged continuously. In this example, the height and width of each convex portion are the same, but the height and width of each convex portion may be different in the electrolysis electrode in embodiment 2. Here, the electrolysis electrode 101B shown in fig. 23 is a plan perspective view of the electrolysis electrode 101B shown in fig. 20.

In the electrolysis electrode 101C shown in fig. 21, the undulation portions (concave portions) 102C are arranged continuously. In this example, the height and width of each concave portion are the same, but the height and width of each convex portion or each concave portion may be different in the electrolysis electrode in embodiment 2.

In the electrolysis electrode according to embodiment 2, the undulation portion preferably satisfies at least one of the following conditions (I) to (III) in at least one direction in the facing surface.

(I) The undulations are each independently arranged.

(II) the undulation is a convex portion, and the convex portions are continuously arranged.

(III) the undulation is a concave portion, and the concave portions are continuously arranged.

By satisfying such conditions, the electrolytic performance tends to be further excellent. Specific examples of the conditions are shown in fig. 19 to 21. That is, fig. 19 corresponds to an example in which the condition (I) is satisfied, fig. 20 corresponds to an example in which the condition (II) is satisfied, and fig. 21 corresponds to an example in which the condition (III) is satisfied.

In the electrolysis electrode according to embodiment 2, it is preferable that the undulation portions are independently arranged in one direction D1 in the facing surfaces. The term "independently disposed" means that the undulating portions are disposed at predetermined intervals with flat portions interposed therebetween, as shown in fig. 19. The flat portion disposed when the condition (I) is satisfied is preferably a portion having a width of 10 μm or more in the direction D1. The uneven portion in the electrolytic electrode generally has residual stress due to uneven working, and the magnitude of the residual stress may affect the handling properties of the electrolytic electrode. That is, from the viewpoint of reducing residual stress and improving the handleability of the electrolysis electrode, the electrolysis electrode in embodiment 2 preferably satisfies the condition (I) as shown in fig. 19. When the condition (I) is satisfied, flatness tends to be ensured without additional processing such as annealing, and the manufacturing process can be simplified.

As shown in fig. 19, the electrolysis electrode according to embodiment 2 is more preferably configured such that the undulation portions are independently arranged in the direction D1 of the electrolysis electrode and in the direction D1' orthogonal to D1. This makes it possible to form a supply path for the raw material for the electrolytic reaction, thereby sufficiently supplying the raw material to the electrode, and to form a diffusion path for the reaction product, thereby smoothly diffusing the reaction product from the electrode surface.

In the electrolysis electrode according to embodiment 2, the undulation portions may be continuously arranged in one direction D2 in the facing surfaces. The "continuous arrangement" means that 2 or more undulating portions are arranged so as to be continuous, as shown in fig. 20 and 21. When the conditions (II) and (III) are satisfied, a minute flat region having a width of less than 10 μm in the direction D2 may be present at the boundary of each undulation.

The electrolysis electrode according to embodiment 2 can satisfy a plurality of conditions among conditions (I) to (III). For example, a region in which 2 or more undulations are continuously arranged and a region in which undulations are arranged independently may be mixed in one direction in the facing surface.

In addition, the mass per unit area of the electrode for electrolysis is preferably 500mg/cm from the viewpoint of obtaining good workability, having good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode, a power supply body not coated with a catalyst, and the like, and further being economical²Hereinafter, more preferably 300mg/cm²The concentration is preferably 100mg/cm or less²The concentration is preferably 50mg/cm or less²The following (preferably 48 mg/cm)²Less than, more preferably 30mg/cm ²The concentration is preferably 20mg/cm or less²Below), and further preferably 15mg/cm from the viewpoint of comprehensive consideration of workability, adhesiveness and economy²The following. The lower limit is not particularly limited, and is, for example, 1mg/cm²Left and right.

For example, the mass per unit area can be set to the above range by appropriately adjusting the aperture ratio, the thickness of the electrode, and the like described in embodiment 1. More specifically, for example, if the thickness is the same, the mass per unit area tends to decrease when the open area ratio increases, and the mass per unit area tends to increase when the open area ratio decreases.

As described above, fig. 10 described in embodiment 1 corresponds to the enlarged portion of the portion surrounded by the broken line P shown in fig. 19, and the electrode base material 10 for electrolysis shown in fig. 10 is preferably a porous form having a plurality of holes formed by punching or the like. This makes it possible to sufficiently supply the reaction raw material to the electrolytic reaction surface and to rapidly diffuse the reaction product. The diameter of each hole is, for example, about 0.1 to 10mm, preferably 0.5 to 5 mm. The aperture ratio is, for example, 10 to 80%, preferably 20 to 60%.

The undulation portion is not necessarily formed in the electrode base material for electrolysis 10, but it is preferable to form the undulation portion satisfying the conditions (i) to (iii). In order to satisfy such conditions, for example, a metal roll and a resin roll having a specific pattern formed on the surface thereof are used as the electrode base material for electrolysis, and the electrode base material is embossed at a linear pressure of 100 to 400N/cm. Examples of the metal roll having a specific pattern formed on the surface thereof include metal rolls shown in fig. 24 (a) and fig. 25 to 27. Both the rectangular outer frames shown in fig. 24 a and fig. 25 to 27 correspond to the shape of the pattern portion of the metal roll in plan view, and the portions surrounded by lines (hatched portions in the respective figures) in the outer frames correspond to the pattern portion (i.e., the undulating portions in the metal roll).

The control for satisfying the conditions (i) to (iii) includes, but is not limited to, the following methods.

By transferring the irregularities formed on the surface of the roller to the electrode base material for electrolysis, the undulation portion of the electrode for electrolysis can be formed. Here, S can be adjusted by, for example, adjusting the number of projections and depressions on the roller surface, the height of the projections, the area of the projections when viewed in plan, or the like_a、S_aveAnd the value of H. More specifically, when the number of irregularities on the roller surface increases, S is_aTends to increase, and when the area of the convex portion of the unevenness on the roller surface is increased in plan view, S is increased_aveThe value of (h + t) tends to increase as the height of the convex portion of the unevenness on the roller surface increases.

In embodiment 2, the separator is laminated on the surface of the electrode for electrolysis. The "surface of the electrolysis electrode" referred to herein may be either one of both surfaces of the electrolysis electrode. Specifically, in the case of the electrodes 101A, 101B, and 101C for electrolysis in fig. 19, 20, and 21, the separators may be laminated on the upper surfaces of the electrodes 101A, 101B, and 101C for electrolysis, or the separators may be laminated on the lower surfaces of the electrodes 101A, 101B, and 101C for electrolysis, respectively.

The diaphragm has a concavo-convex structure on its surface. The ratio a of the volume of the gap between the electrode for electrolysis and the separator to the unit area of the separator is greater than 0.8 μm and 200 μm or less, preferably 13 μm to 150 μm, more preferably 14 μm to 150 μm, and still more preferably 23 μm to 120 μm. When the ratio a is in such a range, the retention of NaOH at the interface can be suppressed, and as a result, the increase in voltage and the decrease in current efficiency can be suppressed, and the electrolytic performance can be improved. The ratio a is determined by the method described in the examples below. The ratio a can be adjusted to the above range by, for example, adjusting the surface shape of the separator (specifically, adjusting the shape of the irregularities, the height or depth of the irregularities, and the frequency of the irregularities). Similarly, the surface shape of the electrode for electrolysis (more specifically, the shape of the irregularities, the height or depth of the irregularities, and the frequency of the irregularities) can be adjusted to the above range. Both the separator and the electrolysis electrode may have a concavo-convex shape. More specifically, the ratio a tends to increase as the height of the irregularities in the electrode for electrolysis and/or the separator increases, and the ratio a tends to increase as the frequency of the irregularities increases.

The separator may have an uneven structure on its surface, may have an uneven structure on both surfaces (for example, an anode surface and a cathode surface) of the separator, or may have an uneven structure on one of both surfaces (for example, the anode surface or the cathode surface) of the separator. The "anode surface" used herein means an interface between an electrolysis electrode and a separator in a laminate of the electrolysis electrode and the separator used as an anode, and the "cathode surface" means an interface between the electrolysis electrode and the separator in a laminate of the electrolysis electrode and the separator used as a cathode. When both surfaces of the separator have the concave-convex structures, the concave-convex structures may be the same or different from each other.

The difference in height, which is the difference between the maximum value and the minimum value of the height in the uneven structure, is preferably greater than 2.5 μm (for example, greater than 2.5 μm and 350 μm or less), and is preferably 45 μm or more, more preferably 46 μm or more, and still more preferably 90 μm or more. When the height difference is within the above range, the retention of NaOH at the above interface can be further suppressed, and as a result, the increase in voltage and the decrease in current efficiency can be further suppressed, and the electrolytic performance can be further improved. The height difference is obtained by the method described in the examples below. The upper limit is not particularly limited, but is preferably 350 μm or less, more preferably 200 μm or less, from the viewpoint of voltage and the like.

The standard deviation of the height difference in the uneven structure is preferably more than 0.3 μm (for example, more than 0.3 μm and 60 μm or less), more preferably 7 μm or more, still more preferably 7 μm or more, and still more preferably 13 μm or more. When the standard deviation is within the above range, the retention of NaOH at the interface can be further suppressed, and as a result, the increase in voltage and the decrease in current efficiency can be further suppressed, and the electrolytic performance can be further improved. The height difference is obtained by the method described in the examples below. The upper limit is not particularly limited, but is preferably 60 μm or less.

The method for producing the ion exchange membrane as the separator in embodiment 2 may be the same as the method for producing the ion exchange membrane described in embodiment 1. That is, a preferred method for producing an ion-exchange membrane includes the following steps (1) to (6).

(1) The process comprises the following steps: a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor which can be an ion exchange group by hydrolysis.

(2) The process comprises the following steps: and if necessary, weaving at least a plurality of reinforcing core materials and sacrificial filaments having a property of dissolving in an acid or an alkali and forming communication holes, thereby obtaining a reinforcing material in which the sacrificial filaments are arranged between adjacent reinforcing core materials.

(3) The process comprises the following steps: and a step of forming a film of the fluorine-containing polymer having an ion exchange group or an ion exchange group precursor which can be an ion exchange group by hydrolysis.

(4) The process comprises the following steps: and a step of embedding the reinforcing material into the film as necessary to obtain a film body having an uneven structure satisfying a specific ratio a on the surface thereof, in which the reinforcing material is arranged inside.

(5) The process comprises the following steps: and (4) hydrolyzing the film body obtained in step (4) (hydrolysis step).

(6) The process comprises the following steps: and (5) providing a coating layer on the film body obtained in the step (5) (coating step).

Here, from the viewpoint of adjusting the ratio a, the step height, and the standard deviation of the step height in embodiment 2 to fall within a desired range, it is preferable to carry out the manufacturing method in consideration of the following matters.

In the step (2), the arrangement of the reinforcing core material and the sacrificial wire can be adjusted to control the aperture ratio, the arrangement of the through holes, and the like. In addition, the uneven structure can be formed on the surface of the ion exchange membrane by adjusting the arrangement of the reinforcing core material. For example, as shown in fig. 13 (a), the reinforcing yarn 52 may be formed in a lattice shape in which warp yarns and weft yarns intersect with each other, thereby forming an uneven structure in which the intersecting portions are convex portions.

The method for forming the uneven structure having projections, that is, the projections, on the surface of the ion exchange membrane is not particularly limited, and a known method for forming projections on the surface of a resin can be used (for example, methods described in japanese patent No. 3075580, japanese patent No. 4708133, and japanese patent No. 5774514). Specifically, for example, a method of embossing the surface of the film body may be mentioned. For example, when the composite film is integrated with a reinforcing material or the like, the convex portion may be formed by laminating a release paper subjected to embossing, the composite film, and the reinforcing material, and removing the release paper by heating and reducing pressure. When the convex portions are formed by embossing, the height and arrangement density of the convex portions can be controlled by controlling the embossing shape (the shape of the release paper) to be transferred.

Further, the following methods may be mentioned: the step of obtaining a film body ((4) step) was performed without using an embossed release paper, and a lattice-like uneven structure of reinforcing threads 52 shown in fig. 13 (a) was formed.

Here, when the uneven structure is formed on the cathode surface of the ion exchange membrane, the following method can be mentioned as a method for increasing the level difference in the uneven structure. That is, the composite film and the reinforcing material may be integrated under heating and pressure reduction conditions such that the heating temperature is about 230 to 235 ℃ and the degree of vacuum is about 0.065 to 0.070MPa, and the heating and pressure reduction may be performed for about 1 to 3 minutes. On the other hand, when the cathode surface of the ion exchange membrane has a concavo-convex structure, the following method can be mentioned as a method for reducing the level difference in the concavo-convex structure. That is, the surface of the film body may be subjected to heating and pressure reduction for about 1 to 3 minutes under heating and pressure reduction conditions for embossing at a heating temperature of about 220 to 225 ℃ and a vacuum degree of about 0.065 to 0.070 MPa. In this case, the step difference can be further reduced by removing the KAPTON film by heating and reducing the pressure in a state where the KAPTON film is laminated on the composite film and the reinforcing material as necessary.

Here, when the uneven structure is formed on the anode surface of the ion exchange membrane, the following method can be mentioned as a method for increasing the level difference in the uneven structure. That is, when the composite film and the reinforcing material are integrated, the PET film, the composite film, and the reinforcing material may be laminated, the PET film may be removed after the PET film is laminated by using a metal roll and a rubber backup roll heated to about 200 ℃. On the other hand, when the ion exchange membrane has an uneven structure on the anode surface, the following method can be mentioned as a method for reducing the level difference in the uneven structure. Examples thereof include: when the composite film is integrated with a reinforcing material or the like, a release paper that is not subjected to embossing or a release paper that is subjected to embossing to a small depth is used.

The standard deviation can be controlled by controlling the heating temperature in the plane direction of the ion exchange membrane, the vacuum degree condition, or the shape of the reinforcing core material, sacrificial thread, release paper, or the like used.

[ electrolytic tank ]

The electrolytic cell of embodiment 2 includes the laminate of embodiment 2. The method for manufacturing an electrolytic cell according to embodiment 2 is a method for manufacturing a new electrolytic cell by disposing a laminate in an existing electrolytic cell including an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode, and includes a step (a)) of exchanging the separator in the existing electrolytic cell with the laminate, the laminate being the laminate according to embodiment 2.

Note that the electrolytic cell and other components constituting the electrolytic cell of embodiment 2 are the same as those in embodiment 1, and therefore redundant description is omitted.

In embodiment 2, the conventional electrolytic cell includes an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode as constituent members, that is, an electrolytic cell. The conventional electrolytic cell is not particularly limited as long as it includes the above-described constituent members, and various known configurations such as the above-described configuration can be applied.

In embodiment 2, the new electrolytic cell further includes an electrode for electrolysis or a laminate in addition to the member already functioning as an anode or a cathode in the existing electrolytic cell. That is, the "electrolysis electrode" disposed when a new electrolytic cell is manufactured functions as an anode or a cathode, and is separate from the cathode and the anode in the conventional electrolytic cell. In embodiment 2, even when the electrolytic performance of the anode and/or the cathode deteriorates with the operation of the existing electrolytic cell, the performance of the anode and/or the cathode can be updated by disposing an electrolysis electrode separate from the former. Further, since a new ion exchange membrane constituting the laminate is also disposed, the performance of the ion exchange membrane whose performance has deteriorated with operation can be renewed at the same time. The term "renewal performance" as used herein means performance equivalent to or higher than the initial performance of the conventional electrolytic cell before the operation.

In embodiment 2, it is assumed that the existing electrolytic cell is the "electrolytic cell already supplied for operation", and the new electrolytic cell is the "electrolytic cell not yet supplied for operation". That is, when an electrolytic cell manufactured as a new electrolytic cell is operated, it constitutes "the existing electrolytic cell in embodiment 2", and an electrolytic cell in which an electrode for electrolysis or a laminate is disposed in the existing electrolytic cell becomes "the new electrolytic cell in embodiment 2".

In the step (a) of embodiment 2, the separator in the existing electrolytic cell is exchanged with the laminate. The method of exchange is not particularly limited, and examples thereof include the following methods: first, the fixing state of the electrolysis unit and the ion exchange membrane adjacent to each other by the pressurizer is released in the existing electrolytic cell, a gap is formed between the electrolysis unit and the ion exchange membrane, the existing ion exchange membrane to be replaced is removed, the laminate is inserted into the gap, and the components are connected by the pressurizer again. By this method, the layered body can be arranged on the surface of the anode or the cathode in the existing electrolytic cell, and the performance of the ion exchange membrane, the anode and/or the cathode can be updated.

< embodiment 3 >

Embodiment 3 of the present invention will be described in detail below.

[ method for producing electrolytic cell ]

A method for manufacturing an electrolytic cell according to claim 1 of embodiment 3 (hereinafter also referred to as "method 1") is a method for manufacturing a new electrolytic cell by disposing electrodes for electrolysis in an existing electrolytic cell including an anode, a cathode facing the anode, a separator disposed between the anode and the cathode, and an electrolytic cell frame including an anode frame supporting the anode and a cathode frame supporting the cathode, and accommodating the anode, the cathode, and the separator by integrating the anode frame and the cathode frame, and includes: a step (A1) of releasing the integration of the anode frame and the cathode frame and exposing the separator; a step (B1) of disposing the electrolysis electrode on at least one surface of the separator after the step (a 1); and a step (C1) of, after the step (B1), integrating the anode frame and the cathode frame to house the anode, the cathode, the separator, and the electrolysis electrode in the electrolysis cell frame.

As described above, according to the method 1, since the performance of at least one of the anode and the cathode can be updated without removing the anode and the cathode by using the existing electrolytic cell, the operation efficiency at the time of updating the components in the electrolytic cell can be improved without involving a series of complicated operations such as taking out of the electrolytic cell, carrying out, removing the old electrode, installing and fixing the new electrode, and carrying and installing the new electrode into the electrolytic cell.

A method for manufacturing an electrolytic cell according to embodiment 2 of embodiment 3 (hereinafter also referred to as "method 2") is a method for manufacturing a new electrolytic cell by disposing an electrode for electrolysis and a new separator in an existing electrolytic cell including an anode, a cathode facing the anode, a separator disposed between the anode and the cathode, and an electrolytic cell frame including an anode frame supporting the anode and a cathode frame supporting the cathode, and accommodating the anode, the cathode, and the separator by integrating the anode frame and the cathode frame, and includes: a step (A2) of releasing the integration of the anode frame and the cathode frame and exposing the separator; a step (B2) of removing the separator after the step (a2) and disposing the electrolysis electrode and a new separator on the anode or the cathode; and a step (C2) of integrating the anode frame and the cathode frame to house the anode, the cathode, the separator, the electrode for electrolysis, and a new separator in the electrolysis cell frame.

As described above, according to the method 2, since the performance of at least one of the anode and the cathode and the performance of the separator can be updated together without removing the anode and the cathode by using the existing electrolytic cell, the operation efficiency at the time of updating the components in the electrolytic cell can be improved without involving a series of complicated operations such as taking out of the electrolytic cell, carrying out, removing the old electrode, installing and fixing the new electrode, and transporting and installing the new electrode into the electrolytic cell.

Hereinafter, when referring to "the manufacturing method of embodiment 3", the 1 st method and the 2 nd method are included.

In the production method of embodiment 3, the conventional electrolytic cell includes, as constituent members, an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode, in other words, an electrolytic cell including at least the anode, the cathode, and the separator as constituent members. The conventional electrolytic cell is not particularly limited as long as it includes the above-described components, and various known configurations can be applied. In the case where the anode of the conventional electrolytic cell is in contact with the electrolysis electrode, the electrolytic cell substantially functions as a power feeder; when not in contact with the electrolysis electrode, it functions as an anode. Similarly, when the cathode of the conventional electrolytic cell is in contact with the electrolysis electrode, it substantially functions as a power feeder; when not in contact with the electrode for electrolysis, it itself functions as a cathode. Here, the power supply means a deteriorated electrode (i.e., an existing electrode), an electrode on which no catalyst is applied, or the like.

In the method 1, the new electrolytic cell is provided with an electrolysis electrode in addition to the anode and the cathode in the conventional electrolytic cell. That is, the electrolysis electrode disposed when a new electrolytic cell is manufactured functions as an anode or a cathode, and is separate from the cathode and the anode in the conventional electrolytic cell. In the method 2, the new electrolytic cell further comprises an electrode for electrolysis and a new separator in addition to the anode and the cathode in the conventional electrolytic cell.

In the method 1, even when the electrolytic performance of the anode and/or the cathode is deteriorated in accordance with the operation of the conventional electrolytic cell, the performance of the anode and/or the cathode can be updated by disposing an electrolysis electrode separate from the former. In addition, in the method 2, since a new separator is also provided, the performance of the separator, which has deteriorated in performance with the operation, can be renewed at the same time.

In the present specification, the term "renewal performance" means performance equivalent to or higher than the initial performance of the conventional electrolytic cell before the operation.

In the production method of embodiment 3, the existing electrolytic cell is assumed to be an "electrolytic cell that has been already supplied for operation", and the new electrolytic cell is assumed to be an "electrolytic cell that has not been supplied for operation". That is, in the manufacturing method of embodiment 3, when an electrolytic cell manufactured as a new electrolytic cell is operated, it constitutes "the existing electrolytic cell in embodiment 3", and an electrolytic cell in which an electrode for electrolysis is arranged in the existing electrolytic cell (in method 2, a new diaphragm is further arranged) becomes "the new electrolytic cell in embodiment 3".

An embodiment of the electrolytic cell will be described in detail below, taking as an example a case of performing salt electrolysis using an ion exchange membrane as a diaphragm. However, in embodiment 3, the electrolytic cell is not limited to salt electrolysis, and may be used for water electrolysis or a fuel cell, for example.

In the present specification, unless otherwise specified, the "electrolytic cell in embodiment 3" is described as including both the "existing electrolytic cell in embodiment 3" and the "new electrolytic cell in embodiment 3".

In addition, the diaphragm in the conventional electrolytic cell and the new diaphragm may have the same shape, material and physical properties. Therefore, in the present specification, unless otherwise specified, "the separator in embodiment 3" is described as including "the separator in the existing electrolytic cell in embodiment 3" and "the new separator in embodiment 3".

[ electrolytic cell ]

First, an electrolytic cell that can be used as a constituent element of the electrolytic cell in embodiment 3 will be described.

FIG. 28 is a sectional view of the electrolysis cell 50.

As shown in fig. 28, the electrolysis cell 50 includes a cation exchange membrane 51, an anode chamber 60 defined by the cation exchange membrane 51 and an anode frame 24, a cathode chamber 70 defined by the cation exchange membrane 51 and a cathode frame 25, an anode 11 provided in the anode chamber 60, and a cathode 21 provided in the cathode chamber 70, wherein the anode 11 is supported by the anode frame 24 and the cathode 21 is supported by the cathode frame 25. In the present specification, when it is referred to as an electrolytic cell frame, it includes an anode frame and a cathode frame. In fig. 28, the cation exchange membrane 51, the anode frame, and the cathode frame 25 are shown separated for convenience of explanation, but they are in contact with each other in a state of being disposed in the electrolytic cell.

The electrolytic cell 50 may have a configuration including a reverse current absorbing member 18 provided in the cathode chamber, if necessary, and the reverse current absorbing member 18 includes a base member 18a and a reverse current absorbing layer 18b formed on the base member 18a (see fig. 31). The anode 11 and the cathode 21 belonging to 1 electrolysis cell 50 are electrically connected to each other. In other words, the electrolysis unit 50 includes the following cathode structure. That is, the cathode structure includes a cathode chamber 70, a cathode 21 provided in the cathode chamber 70, and a reverse current absorbing body 18 provided in the cathode chamber 70, the reverse current absorbing body 18 includes a base 18a and a reverse current absorbing layer 18b formed on the base 18a as shown in fig. 31, and the cathode 21 is electrically connected to the reverse current absorbing layer 18 b. The cathode chamber 70 further includes a current collector 23 and a metal elastic body 22. The metal elastic body 22 is disposed between the current collector 23 and the cathode 21. The current collector 23 is electrically connected to the cathode 21 through the metal elastic body 22. The cathode frame 25 is electrically connected to the current collector 23. Therefore, the cathode frame 25, the current collector 23, the metal elastic body 22, and the cathode 21 are electrically connected. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer may be directly connected or indirectly connected via a current collector, a metal elastic body, a cathode frame, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for reduction reaction. In addition, the electrical connection method may be as follows: the cathode frame 25 and the current collector 23 are directly attached, the current collector 23 and the metal elastic body 22 are directly attached, and the cathode 21 is laminated on the metal elastic body 22. As a method of directly attaching these components to each other, welding and the like are given. The reverse current absorber 18, the cathode 21, and the current collector 23 may be collectively referred to as a cathode structure.

Fig. 29 shows the electrolytic cell 4. FIG. 30 shows an assembly process of the electrolytic cell 4.

As shown in FIG. 29, the electrolytic cell 4 is composed of a plurality of electrolytic cells 50 connected in series. That is, the electrolytic cell 4 is a bipolar type electrolytic cell including a plurality of electrolytic cells 50 arranged in series. Further, as shown in FIGS. 29 to 30, the electrolytic cell 4 is assembled by arranging a plurality of electrolytic cells 50 in series and connecting them by the pressurizer 5.

The electrolytic cell 4 has an anode terminal 7 and a cathode terminal 6 connected to a power supply. Among the plurality of electrolysis cells 50 connected in series in the electrolytic cell 4, the anode 11 of the electrolysis cell 50 located at the endmost portion is electrically connected to the anode terminal 7. Among the plurality of electrolysis cells 2 connected in series in the electrolytic cell 4, the cathode 21 of the electrolysis cell located at the end opposite to the anode terminal 7 is electrically connected to the cathode terminal 6. The current during electrolysis flows from the anode terminal 7 side to the cathode terminal 6 via the anode and cathode of each electrolysis cell 50. Note that an electrolysis cell (anode terminal cell) having only an anode chamber and an electrolysis cell (cathode terminal cell) having only a cathode chamber may be disposed at both ends of the connected electrolysis cell 50. In this case, the anode terminal 7 is connected to an anode terminal unit disposed at one end thereof, and the cathode terminal 6 is connected to a cathode terminal unit disposed at the other end thereof.

When brine is electrolyzed, brine is supplied to each anode chamber 60, and pure water or a low-concentration sodium hydroxide aqueous solution is supplied to the cathode chamber 70. Each liquid is supplied from an electrolyte supply pipe (not shown) to each electrolysis cell 50 through an electrolyte supply hose (not shown). In addition, the electrolytic solution and the products generated by electrolysis are recovered by an electrolytic solution recovery pipe (not shown in the figure). In electrolysis, sodium ions in brine move from the anode chamber 60 to the cathode chamber 70 of one electrolysis cell 50 through the cation exchange membrane 51. Thereby, the current in electrolysis flows in the direction in which the electrolysis cells 50 are connected in series. That is, an electric current flows from anode chamber 60 to cathode chamber 70 through cation exchange membrane 51. With the electrolysis of the brine, chlorine gas is generated on the anode 11 side, and sodium hydroxide (solute) and hydrogen gas are generated on the cathode 21 side.

(Anode compartment)

The anode chamber 60 has an anode 11 or an anode power supply 11. The power feeder referred to herein means a deteriorated electrode (i.e., an existing electrode), an electrode not coated with a catalyst, and the like. When the electrolysis electrode in embodiment 3 is inserted on the anode side, 11 functions as an anode current carrier. When the electrolysis electrode in embodiment 3 is not inserted into the anode side, 11 functions as an anode. In addition, anode chamber 60 preferably has: an anode side electrolyte supply unit for supplying an electrolyte to the anode chamber 60; a baffle plate disposed above the anode side electrolyte supply unit and disposed substantially parallel to or inclined with respect to the anode frame 24; and an anode-side gas-liquid separation unit disposed above the baffle plate and configured to separate gas from the electrolyte into which the gas is mixed.

(Anode)

When the electrolysis electrode in embodiment 3 is not inserted into the anode side, the anode 11 is provided in a frame (i.e., an anode frame) of the anode chamber 60. As the anode 11, a metal electrode such as so-called DSA (registered trademark) can be used. DSA refers to an electrode of a titanium substrate whose surface is coated with an oxide containing ruthenium, iridium, and titanium as components.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(Anode power supply body)

When the electrolysis electrode in embodiment 3 is inserted into the anode side, the anode feeder 11 is provided in the frame of the anode chamber 60. As the anode current collector 11, a metal electrode such as DSA (registered trademark) or the like may be used, or titanium which is not coated with a catalyst may be used. In addition, DSA with a reduced catalyst coating thickness may be used. In addition, a used anode may also be used.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(Anode-side electrolyte supply unit)

The anode side electrolyte supply unit supplies an electrolyte to the anode chamber 60, and is connected to an electrolyte supply pipe. The anode-side electrolyte supply unit is preferably disposed below the anode chamber 60. As the anode-side electrolyte solution supply unit, for example, a tube (dispersion tube) having an opening formed on the surface thereof can be used. The tube is more preferably arranged parallel to the bottom of the electrolysis cell along the surface of the anode 11. This pipe is connected to an electrolyte supply pipe (liquid supply nozzle) for supplying an electrolyte into the electrolysis cell 50. The electrolytic solution supplied from the liquid supply nozzle is transferred into the electrolytic cell 50 through a tube, and is supplied into the anode chamber 60 from an opening provided on the surface of the tube. It is preferable to arrange the tube along the surface of the anode 11 in parallel with the bottom 19 of the electrolytic cell, because the electrolytic solution can be uniformly supplied into the anode chamber 60.

(gas-liquid separator on Anode side)

The gas-liquid separation portion on the anode side is preferably disposed above the baffle plate. In the electrolysis, the anode-side gas-liquid separation section has a function of separating a product gas such as chlorine gas and an electrolytic solution. Unless otherwise specified, the upper side refers to the rightward direction in the electrolytic cell 50 of fig. 28, and the lower side refers to the leftward direction in the electrolytic cell 50 of fig. 28.

When the generated gas generated in the electrolysis unit 50 and the electrolytic solution form a mixed phase (gas-liquid mixed phase) and are discharged to the outside of the system during electrolysis, vibration may occur due to pressure fluctuations inside the electrolysis unit 50, and physical damage to the ion exchange membrane may occur. In order to suppress this phenomenon, it is preferable that the electrolysis cell 50 in embodiment 3 is provided with an anode-side gas-liquid separation unit for separating gas and liquid. A defoaming plate for defoaming bubbles is preferably provided in the anode-side gas-liquid separation section. When the gas-liquid mixed phase flows through the defoaming plate, bubbles are broken, and the gas-liquid mixed phase can be separated into the electrolyte and the gas. As a result, vibration during electrolysis can be prevented.

(baffle plate)

The baffle plate is preferably disposed above the anode-side electrolyte supply unit and substantially parallel to or inclined with respect to the anode frame 24. The baffle plate is a separator that controls the flow of the electrolyte in the anode chamber 60. By providing the baffle plate, the electrolyte (brine, etc.) can be internally circulated in the anode chamber 60, and the concentration thereof can be made uniform. In order to cause the internal circulation, the baffle plate is preferably disposed so as to separate the space near the anode 11 from the space near the anode frame 24. From this point of view, the baffle plate is preferably disposed so as to face the respective surfaces of the anode 11 and the anode frame 24. In the space near the anode partitioned by the baffle plate, the electrolyte concentration (brine concentration) decreases due to the progress of electrolysis, and a generated gas such as chlorine gas is generated. This causes a difference in specific gravity between the gas-liquid in the space near the anode 11 partitioned by the baffle plate and the space near the anode frame 24. By utilizing this difference in specific gravity, the internal circulation of the electrolyte in anode chamber 60 can be promoted, and the concentration distribution of the electrolyte in anode chamber 60 can be made more uniform.

Although not shown in fig. 28, a current collector may be separately provided inside anode chamber 60. The current collector may be made of the same material or have the same structure as the current collector of the cathode chamber described later. In the anode chamber 60, the anode 11 itself may function as a current collector.

(Anode frame)

The anode frame 24 defines an anode chamber 60 with the cation exchange membrane 51. As the anode frame 24, a member known as a separator for electrolysis can be used, and examples thereof include a metal plate obtained by welding a plate made of titanium.

(cathode chamber)

In the cathode chamber 70, 21 functions as a cathode current collector when the electrolysis electrode in embodiment 3 is inserted on the cathode side, and 21 functions as a cathode when the electrolysis electrode in embodiment 3 is not inserted on the cathode side. In the case of having a reverse current sink, the cathode or cathode power supply 21 is electrically connected to the reverse current sink. In addition, the cathode chamber 70 also preferably includes a cathode electrolyte supply unit and a cathode gas-liquid separation unit, similarly to the anode chamber 60. Among the parts constituting the cathode chamber 70, the same parts as those constituting the anode chamber 60 will not be described.

(cathode)

In the case where the electrolysis electrode in embodiment 3 is not inserted into the cathode side, the cathode 21 is provided in the frame (i.e., cathode frame) of the cathode chamber 70. The cathode 21 preferably has a nickel substrate and a catalyst layer coated with the nickel substrate. Examples of the component of the catalyst layer on the nickel base material include metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of the metals. As a method of forming the catalyst layer, plating, alloy plating, dispersion/composite plating, CVD, PVD, thermal decomposition, and spray coating can be cited. These methods may also be combined. The catalyst layer may have a plurality of layers or a plurality of elements as necessary. The cathode 21 may be subjected to a reduction treatment as needed. As the base material of the cathode 21, nickel, a nickel alloy, or a base material obtained by nickel-plating iron or stainless steel may be used.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(cathode power supply body)

When the electrolysis electrode in embodiment 3 is inserted into the cathode side, the cathode power supply 21 is provided in the frame of the cathode chamber 70. The cathode power-supply body 21 may be coated with a catalyst component. The catalyst component may be a component that is originally used as a cathode and remains. Examples of the component of the catalyst layer include metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of the metals. As a method of forming the catalyst layer, plating, alloy plating, dispersion/composite plating, CVD, PVD, thermal decomposition, and spray coating can be cited. These methods may also be combined. The catalyst layer may have a plurality of layers or a plurality of elements as necessary. In addition, nickel, a nickel alloy, or a material obtained by nickel-plating iron or stainless steel without catalyst coating may be used. As the base material of the cathode element 21, nickel, a nickel alloy, or a base material obtained by nickel-plating iron or stainless steel may be used.

As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, metal foil, porous metal foil formed by electroforming, so-called woven mesh made by weaving metal wires, and the like can be used.

(reverse current absorbing layer)

As the material of the reverse current absorbing layer, a material having an oxidation-reduction potential lower than that of the element for the catalyst layer of the cathode can be selected. Examples thereof include nickel and iron.

(Current collector)

The cathode chamber 70 preferably includes a current collector 23. This improves the current collecting effect. In embodiment 3, the current collector 23 is preferably a porous plate and is disposed substantially parallel to the surface of the cathode 21.

The current collector 23 is preferably made of a metal having conductivity, such as nickel, iron, copper, silver, or titanium. The current collector 23 may be a mixture, an alloy, or a composite oxide of these metals. The shape of the current collector 23 may be any shape as long as it functions as a current collector, and may be a plate shape or a mesh shape.

(Metal elastomer)

By providing the metal elastic body 22 between the current collector 23 and the cathode 21, the cathode 21 is pressed against the cation exchange membrane 51, the distance between the anode 11 and the cathode 21 is shortened, and the voltage applied to the entire plurality of electrolysis cells 50 connected in series can be reduced. By reducing the voltage, power consumption can be reduced. Further, when the laminate including the electrolysis electrode and the new separator in embodiment 3 is provided in the electrolysis cell by providing the metal elastic body 22, the electrolysis electrode can be stably maintained at a fixed position by the pressing pressure generated by the metal elastic body 22.

As the metal elastic body 22, a spring member such as a coil spring or a coil, a cushion pad, or the like can be used. As the metal elastic body 22, an appropriate metal elastic body can be suitably used in consideration of stress for pressing the ion exchange membrane and the like. The metal elastic body 22 may be provided on the surface of the current collector 23 on the cathode chamber 70 side, or may be provided on the surface of the anode frame 24 on the anode chamber 60 side. In general, the cathode chamber 70 is divided into two chambers so as to be smaller than the anode chamber 60, and therefore, it is preferable to provide the metal elastic body 22 between the current collector 23 of the cathode chamber 70 and the cathode 21 in terms of the strength of the frame body and the like. The metal elastic body 23 is preferably made of a metal having conductivity, such as nickel, iron, copper, silver, or titanium.

(cathode frame)

The cathode frame 25 defines a cathode chamber 70 together with the cation exchange membrane 51. As the cathode frame 25, a member known as a separator for electrolysis can be used, and examples thereof include a metal plate obtained by welding a nickel plate.

(Anode side gasket, cathode side gasket)

The anode-side gasket 12 is preferably disposed on the surface of the anode frame 24 constituting the anode chamber 60. The cathode-side gasket 13 is preferably disposed on the surface of the cathode frame 25 constituting the cathode chamber 70. The anode frame 24 and the cathode frame 25 are integrated so that the anode-side gasket 12 and the cathode-side gasket 13 of the electrolysis cell 50 sandwich the cation exchange membrane 51 (see fig. 28). When these gaskets are integrated, airtightness can be provided to the joint.

The gasket is a member for sealing between the ion exchange membrane and the electrolytic cell. Specific examples of the gasket include a frame-shaped rubber sheet having an opening formed in the center thereof. The gasket is required to have resistance to corrosive electrolyte, generated gas, and the like and to be usable for a long period of time. Therefore, a vulcanized product or a peroxide crosslinked product of ethylene propylene diene monomer (EPDM rubber) or ethylene propylene diene monomer (EPM rubber) is generally used as a gasket in terms of chemical resistance and hardness. Further, a gasket in which a region in contact with a liquid (liquid contact portion) is coated with a fluorine resin such as Polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) may be used as necessary. The shape of each of these spacers is not particularly limited as long as it has an opening so as not to obstruct the flow of the electrolyte. For example, a frame-shaped gasket is attached with an adhesive or the like along the periphery of each opening of the anode frame 24 constituting the anode chamber 60 or the cathode frame 25 constituting the cathode chamber 70. For example, when the anode frame 24 and the cathode frame 25 are connected to each other through the cation exchange membrane 51 (see fig. 28), the surfaces of the anode frame 24 and the cathode frame 25 to which the gaskets are attached may be fastened so as to sandwich the cation exchange membrane 51. This can prevent the electrolyte solution, alkali metal hydroxide produced by electrolysis, chlorine gas, hydrogen gas, and the like from leaking to the outside of the electrolytic cell 50.

Next, the respective steps in the manufacturing method of embodiment 3 will be described with reference to (a) to (D) of fig. 32. First, the steps (a1) to (C1) in method 1 will be described in detail.

(Process (A1))

The step (a1) in embodiment 3 is a step of releasing the integration of the anode frame and the cathode frame and exposing the separator.

Fig. 32 (a) shows the electrolysis cell 50 in the same manner as fig. 28, and in this state, the anode frame 24 and the cathode frame 25 are integrated. That is, the anode 11, the cathode 21, and the cation exchange membrane 51 are housed in the electrolysis cell frame. The integration is not particularly limited, and examples thereof include a method in which the anode frame 24 and the cathode frame 25 are overlapped and their overlapped ends are clamped by a stainless steel plate having a bolt hole formed therein in advance and fastened by a bolt. In the above example, the integration is released by releasing the bolt fastening in the state of fig. 32 (a), and the cathode frame 25 is separated from the anode frame 24 so as to lift the cathode frame 25, thereby bringing the state shown in fig. 32 (B). In the state of fig. 32 (B), the cation exchange membrane 51 is exposed (step (a 1)).

(Process (B1))

The step (B1) in embodiment 3 is a step of disposing an electrolysis electrode on at least one surface of the separator after the step (a 1).

Fig. 32 (C) shows an example in which the electrolysis electrode 101 is disposed on the exposed surface (exposed surface) of the cation exchange membrane 51. In this case, the electrolysis electrode 101 functions as a cathode. In the step (B1), the electrolytic electrode 101 may be disposed on the surface (opposite surface) of the cation-exchange membrane 51 opposite to the exposed surface, without being limited to this example. In this case, the electrolysis electrode 101 functions as an anode. The electrolysis electrodes 101 may be disposed on both the exposed surface and the opposite surface of the cation-exchange membrane 51. In this case, the electrolysis electrode 101 on the exposed surface functions as a cathode, and the electrolysis electrode 101 on the opposite surface functions as an anode.

(step (C1))

The step (C1) in embodiment 3 is a step of accommodating the anode, the cathode, the separator, and the electrolysis electrode in the electrolysis cell frame by integrating the anode frame and the cathode frame after the step (B1). The integration is not particularly limited, and for example, a method of fixing the anode frame 24 and the cathode frame 25 in a state of being overlapped with each other by clamping the overlapped end portions thereof with a stainless steel plate having a bolt hole formed therein in advance and fastening the plate with a bolt may be mentioned. The state shown in fig. 32 (D) is achieved by the integration.

Fig. 32 (D) shows an example in which the electrolysis electrode 101 is disposed on the exposed surface of the cation exchange membrane 51, and in this case, the cathode 21 functions as a power feeder. In the step (C1), the electrolytic electrode 101 may be disposed on the surface (opposite surface) of the cation-exchange membrane 51 opposite to the exposed surface, without being limited to this example. In this case, the anode 11 functions as a power feeder. The electrolysis electrodes 101 may be disposed on both the exposed surface and the opposite surface of the cation-exchange membrane 51. In this case, both the anode 11 and the cathode 21 function as a power feeder.

Fig. 32 shows an example in which the anode frame 24 is disposed on the lower side and the cathode frame 25 is disposed on the upper side, that is, an example in which the anode frame 24 is placed on the work table 103, but the positional relationship is not limited thereto. The positional relationship between the anode frame 24 and the cathode frame 25 may be reversed, that is, the cathode frame 25 may be placed on the work table 103. In this case, the separator is present on the cathode at the time of the step (a 1).

The method 2 will be described in detail.

(Process (A2))

The step (a2) in embodiment 3 is a step of releasing the integration of the anode frame and the cathode frame and exposing the separator. This step can be performed in the same manner as the step (a1) described above, and can be, for example, the state shown in fig. 33 (a) (the same manner as when the electrolytic cell having the same configuration as that in fig. 32 (a) is set to the state shown in fig. 32 (B)).

(Process (B2))

The step (B2) in embodiment 3 is a step of removing the separator after the step (a2) and disposing the electrode for electrolysis and a new separator on the anode or the cathode. In embodiment 3, the electrode for electrolysis and the new separator may be prepared separately and disposed on the anode or the cathode, or the electrode for electrolysis and the new separator may be disposed on the anode or the cathode simultaneously as a laminate.

In the case of using the laminate, first, the ion exchange membrane 51 is removed in the state shown in fig. 33 (a), and the state shown in fig. 33 (B) is formed. Next, the layered body 104 composed of the electrolysis electrode and the new separator is disposed on the anode 11, whereby the state shown in fig. 33 (C) is achieved.

(step (C2))

The step (C2) in embodiment 3 is a step of integrating the anode frame and the cathode frame to house the anode, the cathode, the separator, the electrode for electrolysis, and the new separator in the electrolysis cell frame. This step can be performed in the same manner as the step (C1). For example, the anode frame 24 and the cathode frame 25 may be overlapped in the state shown in fig. 33 (C), the overlapped ends of the frames may be clamped by a stainless steel plate having a bolt hole formed therein in advance, and the anode, the cathode, the separator, the electrode for electrolysis, and the new separator may be accommodated in the electrolysis cell frame by this method or the like, thereby achieving the state shown in fig. 33 (D).

Fig. 33 shows an example in which the anode frame 24 is disposed on the lower side and the cathode frame 25 is disposed on the upper side, but the positional relationship is not limited to this, and the positional relationship between the anode frame 24 and the cathode frame 25 may be reversed. In this case, the separator is present on the cathode at the time of the step (a 2).

The following describes preferred modes that can be adopted in both the method 1 and the method 2.

In embodiment 3, it is preferable that the electrolysis electrode and/or the separator be wetted with a liquid before the step (B1). Similarly, it is preferable that the electrolysis electrode and/or the separator is wetted with a liquid before the step (B2). In this way, the solvent tends to fix the electrolysis electrode to the separator in the step (B1) or the step (B2). As the liquid, any liquid may be used as long as it is a liquid that can generate surface tension, such as water or an organic solvent. The larger the surface tension of the liquid, the larger the force applied between the separator and the electrolysis electrode, and therefore a liquid having a large surface tension is preferred. Examples of the liquid include the following (the value in parentheses is the surface tension of the liquid at 20 ℃).

Hexane (20.44mN/m), acetone (23.30mN/m), methanol (24.00mN/m), ethanol (24.05mN/m), ethylene glycol (50.21mN/m), water (72.76mN/m)

In the case of a liquid having a large surface tension, the separator and the electrolysis electrode are easily integrated, and the electrolysis electrode tends to be more easily fixed to the separator in the step (B1) or the step (B2). The amount of the liquid between the separator and the electrolysis electrode may be such that the liquid adheres to each other by surface tension, and as a result, the amount of the liquid is small, and therefore, even if the liquid is mixed into the electrolytic solution during operation of the electrolytic cell, the liquid does not affect the electrolysis itself.

From the practical viewpoint, it is preferable to use a liquid having a surface tension of 24mN/m to 80mN/m, such as ethanol, ethylene glycol, or water. Particularly, water or an aqueous solution obtained by dissolving sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate, or the like in water to be alkaline is preferable. In addition, these liquids may contain a surfactant to adjust the surface tension. The inclusion of the surfactant changes the adhesiveness between the separator and the electrolysis electrode, and thus the workability can be adjusted. The surfactant is not particularly limited, and any of an ionic surfactant and a nonionic surfactant can be used.

In embodiment 3, it is preferable that the amount of the aqueous solution adhering to the electrolysis electrode per unit area is 1 to 1000g/m in order to facilitate fixing of the electrolysis electrode to the separator ²Is appropriately carried out within the range ofAnd (6) adjusting. The amount of the deposit can be measured by the method described in the examples below.

In the step (B1) in embodiment 3, the angle between the horizontal plane and the placement surface of the electrolysis electrode on the separator is preferably 0 ° or more and less than 90 °. Similarly, in the step (B2), the angle between the horizontal plane and the placement surface of the electrolysis electrode with respect to the separator is preferably 0 ° or more and less than 90 °.

In the example of fig. 32 (a), the electrolysis unit 50 according to embodiment 3 is placed on a work table 103. More specifically, the electrolysis unit 50 is placed on the electrolysis unit placement surface 103a on the work table 103. Typically, the electrolytic cell placement surface 103a of the work table 103 is parallel to a horizontal plane (a plane perpendicular to the direction of gravity), and the placement surface 103a can be regarded as a horizontal plane. In the example of fig. 32 (C), the mounting surface 51a of the electrolysis electrode 101 on the ion exchange membrane 51 is parallel to the electrolysis cell mounting surface 103a of the work table 103. In this example, the angle between the horizontal plane and the mounting surface of the electrolysis electrode with respect to the separator was 0 °. The mounting surface 51a of the electrolysis electrode 101 on the ion exchange membrane 51 may be inclined with respect to the electrolysis cell mounting surface 103a on the work table 103, and the inclination is preferably 0 ° or more and less than 90 ° as described above. The same applies to the step (B2).

From the above-described aspect, the angle between the horizontal plane and the mounting surface of the electrolysis electrode with respect to the separator is more preferably 0 ° to 60 °, and still more preferably 0 ° to 30 °.

In the step (B1) in embodiment 3, it is preferable that the electrolysis electrode is placed on the surface of the separator and planarized. Similarly, in the step (B2) in embodiment 3, it is preferable that the electrolysis electrode is placed on the anode or the cathode, a new separator is placed on the electrolysis electrode, and the new separator is flattened.

In the above-mentioned planarization, a planarization unit may be used, and in the step (B1) and the step (B2), the contact pressure of the planarization unit with respect to the new separator is preferably adjusted to an appropriate range, and for example, a value obtained by measurement by the method described in the later-described examples is preferably 0.1gf/cm²～1000gf/cm²The range of (1).

In the step (B1) in embodiment 3, it is preferable that the electrolysis electrode is positioned so as to cover the current-carrying surface on the separator. Here, the "energization surface" corresponds to a portion of the surface of the diaphragm designed in such a manner that the movement of the electrolyte between the anode chamber and the cathode chamber is performed.

In view of the above, in the step (B2) in embodiment 3, when the electrolysis electrode and the new separator are prepared separately and placed on the anode or the cathode, the electrolysis electrode is preferably positioned so that the electrolysis electrode covers the current-carrying surface on the separator. In the step (B2), when the electrolysis electrode and the new separator are simultaneously disposed on the anode or the cathode in the form of a laminate, it is preferable to position the electrolysis electrode so that the current-carrying surface on the separator is covered with the electrolysis electrode when the laminate is produced.

In the step (B1) in embodiment 3, a wound body in which an electrolysis electrode is wound is preferably used.

Specific examples of the step using the roll are preferably, but not limited to, the following: in the example shown in fig. 32 (B), the roll is disposed on the ion exchange membrane 51, and then the roll is released from the ion exchange membrane 51, and the electrolysis electrode 101 is disposed on the ion exchange membrane 51 as shown in fig. 32 (C). In embodiment 3, the electrolysis electrode may be directly wound to form a wound body, or the electrolysis electrode may be wound around a core to form a wound body. The core that can be used here is not particularly limited, and for example, a member having a substantially cylindrical shape and a size corresponding to the electrolysis electrode can be used. The electrolysis electrode used as the roll is not particularly limited as long as it can be rolled, and the material, shape, and the like thereof are possible, and the roll can be produced by appropriately selecting an appropriate material, shape, and the like in consideration of the step of using the roll, the configuration of the electrolytic cell, and the like in embodiment 3. Specifically, an electrode for electrolysis of a preferred embodiment described later can be used.

In the same manner as described above, in the step (B2), it is preferable to use a roll formed by winding the electrode for electrolysis or a laminate composed of the electrode for electrolysis and a new separator.

[ layered body ]

As described above, the electrode for electrolysis in embodiment 3 can be used in the form of a laminate with a separator such as an ion exchange membrane or a microporous membrane. That is, the laminate of embodiment 3 includes an electrode for electrolysis and a separator. The new laminate in embodiment 3 includes the new electrode for electrolysis and the new separator, and as described above, the new laminate is not particularly limited as long as it is a separate body from the existing laminate in the existing electrolytic cell, and may have the same configuration as the laminate.

[ electrode for electrolysis ]

In embodiment 3, the electrolysis electrode is not particularly limited, but is preferably an electrolysis electrode capable of forming a laminate with the separator as described above, and is also preferably an electrolysis electrode used in the form of a roll. The electrolysis electrode may function as a cathode or as an anode in the electrolytic cell. The material, shape, physical properties, and the like of the electrolysis electrode can be appropriately selected in consideration of the steps in the production method of embodiment 3, the structure of the electrolytic cell, and the like. In embodiment 3, the electrolysis electrodes described in embodiment 1 and embodiment 2 can be preferably used, but these are merely examples of preferred embodiments, and electrolysis electrodes other than the electrolysis electrodes described in embodiment 1 and embodiment 2 can also be suitably used.

[ separator ]

In embodiment 3, the separator is not particularly limited, but is preferably a separator capable of forming a laminate with an electrode for electrolysis as described above, and is also preferably a separator that is used in the form of a roll after being formed into a laminate. The material, shape, physical properties, and the like of the separator can be appropriately selected in consideration of the steps in the production method of embodiment 3, the structure of the electrolytic cell, and the like. Specifically, in embodiment 3, the separators described in embodiment 1 and embodiment 2 can be preferably used, but these are merely examples of the preferred embodiments, and separators other than the separators described in embodiment 1 and embodiment 2 can be suitably used.

Examples

The present embodiment will be described in more detail with reference to the following examples and comparative examples, but the present embodiment is not limited to the following examples.

< verification of embodiment 1 >

As described below, experimental examples corresponding to embodiment 1 (hereinafter, simply referred to as "examples" in the term of < verification of embodiment 1 >) and experimental examples not corresponding to embodiment 1 (hereinafter, simply referred to as "comparative examples" in the term of < verification of embodiment 1 >) were prepared and evaluated by the following methods.

[ laminates used in examples and comparative examples ]

(diaphragm)

As the separator used for producing the laminate, an ion exchange membrane a produced as follows was used.

As the reinforcing core material, a Polytetrafluoroethylene (PTFE) monofilament of 90 denier (hereinafter referred to as PTFE yarn) was used. As the sacrificial yarn, yarn obtained by twisting polyethylene terephthalate (PET) of 35 denier and 6 filaments at 200 times/m (hereinafter referred to as PET yarn) was used. First, in both TD and MD directions, a woven fabric was obtained by plain-weaving PTFE filaments at 24 filaments/inch and sacrificial filaments arranged at 2 filaments between adjacent PTFE filaments. The obtained woven fabric was pressed against a roller to obtain a reinforcing material as a woven fabric having a thickness of 70 μm.

Next, resin A (which is CF) which is a dried resin having an ion exchange capacity of 0.85mg equivalent/g was prepared₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOCH₃Copolymer of (B), resin B (which is CF) which is a dry resin having an ion exchange capacity of 1.03mg equivalent/g₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂Copolymers of F).

Using these resin A and resin B, a 2-layer film X having a resin A layer thickness of 15 μm and a resin B layer thickness of 84 μm was obtained by a coextrusion T-die method. A single-layer film Y having a thickness of 20 μm was obtained by the T-die method using only the resin B.

Subsequently, a release paper (conical embossing having a height of 50 μm), a film Y, a reinforcing material, and a film X were sequentially laminated on a hot plate having a heating source and a vacuum source inside and having fine holes on the surface thereof, and the release paper was removed after heating and pressure reduction for 2 minutes under conditions of a hot plate surface temperature of 223 ℃ and a vacuum degree of 0.067MPa, thereby obtaining a composite film. The film X is laminated in the following manner with the resin B.

The obtained composite membrane was immersed in an aqueous solution containing 30 mass% of dimethyl sulfoxide (DMSO) and 15 mass% of potassium hydroxide (KOH) at 80 ℃ for 20 minutes, thereby performing saponification. Thereafter, the substrate was immersed in an aqueous solution containing sodium hydroxide (NaOH)0.5N at 50 ℃ for 1 hour to replace the counter ion of the ion exchange group with Na, followed by water washing. Thereafter, the surface of the side of the resin B was polished at a relative speed of 100 m/min and a pressing amount of 2mm to form an opening portion, and then dried at 60 ℃.

Further, 20 mass% of zirconia having a 1-order particle diameter of 1 μm was added to a 5 mass% ethanol solution of an acid resin of resin B, and dispersed to prepare a suspension, and the suspension was sprayed on both surfaces of the composite film by a suspension spraying method to form a zirconia coating layer on the surface of the composite film, thereby obtaining an ion exchange membrane a as a separator.

The coating density of zirconia was measured by fluorescent X-ray measurement, and found to be 0.5mg/cm². Here, the average particle diameter was measured by a particle size distribution meter ("SALD (registered trademark) 2200", manufactured by shimadzu corporation).

(electrode for electrolysis)

As the electrode for electrolysis, the following electrodes were used.

A nickel foil having a width of 280mm, a length of 2500mm and a thickness of 22 μm was prepared.

One surface of the nickel foil is subjected to a surface roughening treatment by nickel plating.

The arithmetic average roughness Ra of the roughened surface was 0.95. mu.m.

For the surface roughness measurement, a stylus surface roughness measuring instrument SJ-310 (Mitutoyo, K.K.) was used.

The measurement sample was set on a surface plate parallel to the ground, and the arithmetic average roughness Ra was measured under the following measurement conditions. In the measurement, when 6 times of the measurement were carried out, the average value thereof was recorded.

< shape of contact pin > cone angle 60 °, tip radius 2 μm, and static measurement force 0.75mN

< roughness standard > JIS2001

< evaluation Curve > R

< Filter > GAUSS

< cut-off wavelength value λ c >0.8mm

< cut-off wavelength value λ s >2.5 μm

< number of intervals >5

< front walk, rear walk > have

A circular hole having a diameter of 1mm was punched in the nickel foil to prepare a porous foil. The open porosity was 44%.

The coating liquid for forming the electrode catalyst was prepared as follows.

A ruthenium nitrate solution (Furuya Metal, K.K.) having a ruthenium concentration of 100g/L and cerium nitrate (Kishida chemical) were mixed so that the molar ratio of the ruthenium element to the cerium element was 1: 0.25. The mixture was sufficiently stirred to prepare a cathode coating solution.

The pan containing the coating liquid was set to the lowermost part of the roll coater. A coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an independent bubble type foamed EPDM (ethylene propylene diene monomer) wound around a cylinder made of PVC (polyvinyl chloride) was set so as to be always in contact with the coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon.

The electrode base material was passed between the 2 nd coating roll and the uppermost PVC roll to apply the coating solution (roll coating method). Thereafter, the plate was dried at 50 ℃ for 10 minutes, pre-fired at 150 ℃ for 3 minutes, and fired at 350 ℃ for 10 minutes. These operations of coating, drying, pre-firing and firing are repeated until a predetermined coating amount is reached.

The thickness of the prepared electrode for electrolysis was 29 μm. The thickness of the catalyst layer containing ruthenium oxide and cerium oxide was the difference obtained by subtracting the thickness of the electrode base material for electrolysis from the thickness of the electrode for electrolysis, and was 7 μm each.

A coating layer was also formed on the surface which was not roughened.

[ evaluation of electrolytic Properties of laminates ]

The electrolytic performance was evaluated by the following electrolytic experiment.

An anode cell made of titanium having an anode chamber provided with an anode and a cathode cell having a cathode chamber made of nickel having a cathode are opposed to each other. A pair of pads was disposed between the cells, and a laminate of samples for measurement (the laminate of samples for measurement was a sample laminate obtained by cutting a laminate produced in each example and comparative example described later into a 170mm square) was sandwiched between the pair of pads.

Thereafter, the anode unit, the gasket, the ion exchange membrane, the gasket, and the cathode were closely attached to obtain an electrolytic unit.

An anode was produced by applying a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride to a titanium substrate subjected to sandblasting and acid etching as pretreatment, drying the resultant, and firing the resultant.

The anode is fixed to the anode chamber by welding.

As the current collector of the cathode chamber, a nickel metal mesh was used. The current collector had dimensions of 95mm in length by 110mm in width.

As the metal elastic body, a pad woven with a nickel thin wire was used. A pad as a metal elastomer is placed on the current collector. A nickel mesh obtained by plain-weaving a nickel wire having a diameter of 150 μm with a mesh of 40 mesh was covered on the current collector, and four corners of the Ni mesh were fixed to the current collector with strings made of teflon (registered trademark). The Ni mesh was used as a power supply.

In this electrolytic cell, a zero-pitch structure is formed by the repulsive force of the pad as a metal elastic body.

As the gasket, a rubber gasket made of EPDM (ethylene propylene diene monomer) was used.

The electrolysis of the salt is carried out using the electrolysis cell described above.

The brine concentration (sodium chloride concentration) in the anode compartment was adjusted to 205 g/L.

The sodium hydroxide concentration in the cathode chamber was adjusted to 32 mass%.

The respective temperatures of the anode chamber and the cathode chamber were adjusted in such a manner that the temperature in each electrolysis cell was 90 ℃.

At 6kA/m²The current density of (2) was measured by performing salt electrolysis, and the voltage, current efficiency, and salt concentration in sodium hydroxide were measured.

The salt concentration in sodium hydroxide represents a value converted to 50% of the sodium hydroxide concentration.

[ example 1-1]

An electrode roll and a separator roll as wound bodies were prepared in advance as follows.

First, an ion exchange membrane having a width of 300mm and a length of 2800mm was prepared as a separator by the method described above.

Further, an electrode for electrolysis having a thickness of 29 μm, a width of 280mm and a length of 2500mm was prepared by the method described above.

The ion exchange membrane was immersed in pure water for one day and night, and then wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76mm and a width of 400mm so that the carboxylic acid layer side was the outer side, to prepare a wound body.

Similarly, the electrode was wound around a PVC pipe having an outer diameter of 76mm and a width of 400mm so that the roughened surface was outward, to prepare a wound body.

In this way, a roll of the ion exchange membrane (solid line) shown in fig. 34 (roll 1) and a roll of the electrolysis electrode (broken line) shown in fig. 35 (roll 2) were produced.

As shown in fig. 36, the roll 1 and the roll 2 are arranged, and a laminate is produced while simultaneously drawing out the electrolysis electrode and the ion exchange membrane.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

2800mm was drawn out, and a laminate was easily produced without wrinkles or breakage.

From the laminate produced in example 1-1, samples for evaluation of electrolytic performance were cut out in a size of 170mm square, and electrolytic evaluation was performed.

The laminate was placed with the electrolysis electrode surface facing the cathode current-supplying body.

The evaluation results of the electrolytic performance are shown in table 1 below.

[ examples 1-2]

The same wound body 1 and wound body 2 as in example 1-1 were prepared.

The arrangement of the roll was reversed from that of example 1-1, and as shown in FIG. 37, the roll 1 and the roll 2 were arranged, and a laminate was produced while simultaneously drawing out the electrolysis electrode and the ion exchange membrane.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

2800mm was drawn out, and a laminate was easily produced without wrinkles or breakage. The electrolytic electrode did not fall down.

[ examples 1 to 3]

The same wound body 1 and wound body 2 as in example 1-1 were prepared. The surface of the roll 2 on which the roughening treatment is performed is the inner side.

As shown in fig. 38, the roll 1 and the roll 2 were arranged in the transverse direction, and the wrap angle of the electrolysis electrode with respect to the separator roll was set to about 150 °, and a laminate was produced while simultaneously drawing out the electrolysis electrode and the ion exchange membrane.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

The thickness was 2800mm, and a laminate was perfectly produced without wrinkles and fractures.

As shown in fig. 39, even when the wrap angle of the electrolysis electrode is 0 °, the electrode is laminated on the ion exchange membrane so as to be adsorbed by the surface tension of water adhering to the ion exchange membrane.

2800mm was drawn out, and a laminate was easily produced without wrinkles or breakage.

In fig. 38 and 39, even if the positions of the roll 1 and the roll 2 are changed, the multilayer body can be easily produced. In the case of replacement, the roll 1 is set so that the carboxylic acid layer side is the outer side.

[ examples 1 to 4]

Wound body 1 and wound body 2 were prepared in the same manner as in example 1-1.

As shown in fig. 40, the roll 1 and the roll 2 were arranged in the horizontal direction, and the wrap angle of the electrolysis electrode with respect to the separator roll was set to about 230 ° of 180 ° or more, and a laminate was produced while simultaneously drawing out the electrolysis electrode and the ion exchange membrane.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

2800mm was drawn out, and a laminate was easily produced without wrinkles or breakage.

In fig. 40, even when the positions of the roll 1 and the roll 2 are changed, the multilayer body is easily manufactured. In the case of replacement, the roll 1 is set so that the carboxylic acid layer side is the outer side.

[ examples 1 to 5]

Wound body 1 and wound body 2 were prepared in the same manner as in example 1-1. The surface of the roll 2 on which the roughening treatment is performed is the inner side.

In examples 1 to 5, a polyvinyl chloride (PVC) pipe having an outer diameter of 76mm and a width of 400mm was further prepared as a guide roll (the same PVC pipe as that used for the wound bodies 1 and 2).

As shown in fig. 41, a roll 1 and a roll 2 were arranged, and an electrode for electrolysis was fed through a guide roll, and a laminate was produced while simultaneously drawing out the electrode for electrolysis and an ion exchange membrane.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

The thickness was 2800mm, and a laminate was perfectly produced without wrinkles and fractures.

As shown in fig. 42, even if the wrap angle is 0 °, a laminate can be easily produced without wrinkles or fractures.

In fig. 41 and 42, even when the positions of the roll 1 and the roll 2 are changed, the multilayer body is easily manufactured. In the case of replacement, the roll 1 is set so that the carboxylic acid layer side is the outer side.

[ examples 1 to 6]

Wound body 1 and wound body 2 were prepared in the same manner as in example 1-1. The surface of the roll 2 on which the roughening treatment is performed is the inner side.

In examples 1 to 6, a polyvinyl chloride (PVC) pipe having an outer diameter of 76mm and a width of 400mm was further prepared as a roll (the same PVC pipe as that used for the wound bodies 1 and 2).

As shown in fig. 43, the roll 1 and the roll 2 were arranged, and the electrolysis electrode was fed through a roll, and a laminate was produced while the electrolysis electrode and the ion exchange membrane were simultaneously drawn out.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

2800mm was drawn out, and a laminate was easily produced without wrinkles or breakage.

In fig. 43, even if the positions of the roll 1 and the roll 2 are changed, the multilayer body is easily manufactured. In the roll 1, the carboxylic acid layer side is the outer side.

[ examples 1 to 7]

Wound body 1 and wound body 2 were prepared in the same manner as in example 1-1. The surface of the roll 2 on which the roughening treatment is performed is the inner side.

In examples 1 to 7, 2 polyvinyl chloride (PVC) pipes having an outer diameter of 76mm and a width of 400mm were prepared as a set of rolls (the same PVC pipes as those used for the wound bodies 1 and 2).

As shown in fig. 44, the roll 1 and the roll 2 were arranged, and the electrode for electrolysis was fed through a roll to produce a laminate while simultaneously drawing out the electrode for electrolysis and the ion exchange membrane.

The electrolysis electrode is adsorbed and laminated on the ion exchange membrane by the surface tension of water adhering to the ion exchange membrane.

2800mm was drawn out, and a laminate was easily produced without wrinkles or breakage.

In fig. 44, even if the positions of the roll 1 and the roll 2 are changed, the multilayer body is easily manufactured. In the case of replacement, the roll 1 is set so that the carboxylic acid layer side is the outer side.

In each of the above examples, pure water was supplied to the ion exchange membrane in advance to wet the membrane, and it was confirmed that a laminate can be easily produced by using an ion exchange membrane equilibrated with an aqueous sodium bicarbonate solution or an aqueous caustic alkali solution.

The guide rolls and the rolling rolls are typically arranged, but may be arranged arbitrarily.

Comparative examples 1 to 1

In comparative example 1-1, a membrane electrode assembly in which electrodes were thermocompression bonded to a separator was prepared with reference to the prior art document (example of jp 58-48686 a).

As an electrode substrate for cathode electrolysis, electrode coating was carried out in the same manner as in [ example 1-1] above using a nickel metal lath having a gauge thickness of 100 μm and an opening ratio of 33%. Thereafter, one surface of the electrode was subjected to an inert treatment by the following procedure.

A polyimide tape (Zhongxing chemical Co., Ltd.) was attached to one surface of the electrode, and a PTFE dispersion (31-JR, Mitsui Dupont fluorochemicals) was applied to the opposite surface, followed by drying in a muffle furnace at 120 ℃ for 10 minutes. The polyimide tape was peeled off, and the polyimide tape was subjected to a sintering treatment in a muffle furnace set at 380 ℃ for 10 minutes. This operation was repeated 2 times, and one surface of the electrode was inerted.

Prepared by reacting a terminal functional group of-COOCH₃"perfluorocarbon polymer (C polymer) and having end group of" -SO₂Of perfluorocarbon polymers (S polymers) of F ″2 layers of film. The thickness of the C polymer layer was 3 mils (mil) and the thickness of the S polymer layer was 4 mils (mil). The 2-layer membrane was subjected to saponification treatment, and an ion exchange group was introduced into the terminal of the hydrolyzed polymer. The C polymer end is hydrolyzed to a carboxylic acid group and the S polymer end is hydrolyzed to a sulfo group. The ion exchange capacity was 1.0meq/g for the sulfonic acid group and 0.9meq/g for the carboxylic acid group.

The surface of the inert electrode is placed opposite to the surface having a carboxylic acid group as an ion exchange group, and hot pressing is performed to integrate the ion exchange membrane and the electrode. After thermocompression bonding, one surface of the electrode is exposed, and there is no portion where the electrode penetrates the film.

Thereafter, in order to suppress the adhesion of bubbles generated during electrolysis to the membrane, a mixture of zirconia and a perfluorocarbon polymer having sulfonic groups introduced thereto was applied to both sides. Thus, a membrane electrode assembly of comparative example 1-1 was produced.

In order to produce a membrane electrode assembly as a laminate, a plurality of steps are required, and a period of one day or more is required to produce the laminate.

As a result of the evaluation of the electrolytic performance, the voltage was high, the current efficiency was low, the salt concentration (50% equivalent) in sodium hydroxide was high, and the electrolytic performance was remarkably deteriorated. The evaluation results are shown in table 1 below.

[ Table 1]

	voltage/V	Current efficiency/%)	Common salt concentration in sodium hydroxide/ppm
				Examples 1 to 1	2.95	97.2	18
Comparative example 1-1	3.67	93.8	226

< verification of embodiment 2 >

As described below, experimental examples corresponding to embodiment 2 (hereinafter, simply referred to as "examples" in the term of < verification of embodiment 2 >) and experimental examples not corresponding to embodiment 2 (hereinafter, simply referred to as "comparative examples" in the term of < verification of embodiment 2 >) were prepared and evaluated by the following methods.

[ production of ion exchange Membrane F2 ]

As the separator used for producing the laminate, an ion exchange membrane F2 produced as follows was used.

As the reinforcing core material, a Polytetrafluoroethylene (PTFE) monofilament of 90 denier (hereinafter referred to as PTFE yarn) was used. As the sacrificial yarn, yarn obtained by twisting polyethylene terephthalate (PET) of 35 denier and 6 filaments at 200 times/m (hereinafter referred to as PET yarn) was used. First, in both TD and MD directions, a woven fabric was obtained by plain-weaving PTFE filaments at 24 filaments/inch and sacrificial filaments arranged at 2 filaments between adjacent PTFE filaments. The obtained woven fabric was pressed against a roller to obtain a reinforcing material as a woven fabric having a thickness of 70 μm.

Next, resin A (which is CF) which is a dried resin having an ion exchange capacity of 0.85mg equivalent/g was prepared₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOCH₃Copolymer of (B), resin B having an ion exchange capacity of 1.03mg equivalent/g of dry resin(which is CF)₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂Copolymers of F).

Using these resin A and resin B, a 2-layer film X having a resin A layer thickness of 15 μm and a resin B layer thickness of 84 μm was obtained by a coextrusion T-die method. A single-layer film Y having a thickness of 20 μm was obtained by the T-die method using only the resin B.

Subsequently, a release paper (conical embossing having a height of 50 μm), a film Y, a reinforcing material, and a film X were sequentially laminated on a hot plate having a heating source and a vacuum source inside and having fine holes on the surface thereof, and the release paper was removed after heating and pressure reduction for 2 minutes under conditions of a hot plate surface temperature of 233 ℃ and a vacuum degree of 0.067MPa, thereby obtaining a composite film. The film X is laminated in the following manner with the resin B.

The obtained composite membrane was immersed in an aqueous solution containing 30 mass% of dimethyl sulfoxide (DMSO) and 15 mass% of potassium hydroxide (KOH) at 80 ℃ for 20 minutes, thereby performing saponification. Thereafter, the substrate was immersed in an aqueous solution containing sodium hydroxide (NaOH)0.5N at 50 ℃ for 1 hour to replace the counter ion of the ion exchange group with Na, followed by water washing. Thereafter, the surface of the side of the resin B was polished at a relative speed of 100 m/min and a pressing amount of 2mm to form an opening portion, and then dried at 60 ℃.

Further, 20 mass% of zirconia having a 1-order particle diameter of 1 μm was added to a 5 mass% ethanol solution of an acid resin of resin B, and dispersed to prepare a suspension, and the suspension was sprayed on both surfaces of the composite film by a suspension spraying method to form a coating layer of zirconia on the surface of the composite film, thereby obtaining an ion exchange membrane F2 as a separator. The ion-exchange membrane F2 thus obtained had an uneven structure on both surfaces, an uneven shape from a release paper was provided on the anode surface side of both surfaces, and an uneven shape from a core material was provided on the cathode surface side of both surfaces.

The coating density of zirconia was measured by fluorescent X-ray measurement, and found to be 0.5mg/cm². Here, the average particle diameter was measured by a particle size distribution meter (Shimadzu corporation)Manufactured "SALD (registered trademark) 2200") was measured.

[ evaluation of interfacial Water content w ]

The interfacial water content w of the laminate was evaluated by the following formula.

w＝(T－e－m－(E－e/2)－(M－m/2))/(1－P/100)

w: water content per unit electrode area at membrane/electrode interface (water content at membrane/electrode interface)/g/m²

T: weight/g of moisture-retaining laminate

e: dry weight/g of electrode for electrolysis

E: weight/g of electrode for electrolysis retaining moisture

m: weight/g of ion exchange membrane from which surface-attached moisture was removed

M: weight/g of ion exchange Membrane retaining moisture

P: opening ratio of electrode for electrolysis/%)

Method for measuring e

The electrodes for electrolysis were cut into 200mm × 200mm sizes. The mixture was stored in a 50 ℃ desiccator for 30 minutes or more, dried and then weighed. This operation was performed 5 times, and an average value was obtained.

Method for measuring E

The above-mentioned electrode for electrolysis was stored in a dish to which pure water at 25 ℃ was added for 1 hour. The electrodes were held at one of the four corners of the electrodes and lifted up for 20 seconds to allow the naturally dropped water to drop, thereby controlling the water. After 20 seconds, weighing was carried out immediately. This operation was performed 5 times, and an average value was obtained.

Method for measuring m

An ion exchange membrane of 200mm by 200mm was equilibrated for 24 hours in a pan to which pure water of 25 ℃ was added. The ion-exchange membrane was taken out of the pure water and sandwiched between KimTowel (Nippon paper Crecia) and a resin roll having a width of 200mm and a weight of 300g was reciprocated 2 times to remove water adhering to the surface of the ion-exchange membrane. Immediately thereafter, weighing was performed. This operation was performed 5 times, and an average value was obtained.

Method for measuring M

The ion exchange membrane was cut into a size of 200mm × 200mm, and equilibrated in a pan to which pure water at 25 ℃ was added for 24 hours. Holding one end of four corners of the ion exchange membrane and lifting, keeping for 20 seconds, and allowing naturally dropped water to drop, thereby controlling the water. After 20 seconds, weighing was carried out immediately. This operation was performed 5 times, and an average value was obtained.

Method for measuring T

The ion exchange membrane was cut into a size of 200mm × 200mm, and the electrode for electrolysis was cut into a size of 200mm × 200 mm. The ion exchange membrane and the electrode for electrolysis are laminated by utilizing the surface tension of water existing on the surface of the ion exchange membrane. The laminate was equilibrated in a pan to which pure water at 25 ℃ was added for 24 hours. Holding one end of the four corners of the laminate and lifting the laminate for 20 seconds to allow the naturally dripping water to fall, thereby controlling the water. Weighing was carried out immediately after 20 seconds. This operation was performed 5 times, and an average value was obtained.

Method for measuring P

The electrodes for electrolysis were cut into a size of 200mm × 200 mm. The surface area was uniformly measured at 10 points using a digital thickness gauge (manufactured by Mitutoyo corporation, 0.001mm minimum), and the average value was calculated. The volume was calculated by using the thickness of the electrode (gauge thickness). Thereafter, the mass was measured by an electronic balance, and the specific gravity of the metal (specific gravity of nickel: 8.908 g/cm)³Specific gravity of titanium is 4.506g/cm³) And calculating the opening rate or the void ratio.

Open pore ratio (porosity) (%) (1- (electrode mass)/(electrode volume × specific gravity of metal)) × 100

[ evaluation of ratio a (ratio a of interstitial volume to unit area of separator, also referred to as interstitial volume/area) and uneven structure based on X-ray CT measurement ]

The ratio a of the ion-exchange membrane and the uneven structure of the ion-exchange membrane were evaluated by X-ray CT. As the X-ray CT apparatus and image processing software used, the following apparatus and software are used.

High resolution 3DX microscope nano3DX manufactured by Rigaku corporation of X-ray CT apparatus Ltd

Image analysis software ImageJ

A sample of an ion exchange membrane for X-ray CT measurement was cut into 5 mm. times.5 mm, immersed in pure water, wiped to remove excess water, placed under a 500g weight, dried at room temperature for 24hr, and then subjected to X-ray CT measurement. The measurement conditions are as follows.

Pixel resolution 2.16 μm/pix

Exposure time 8 seconds/piece

Projection number 1000 pieces/180 degree

X-ray tube voltage 50kV

X-ray tube current 24mA

X-ray target Mo

The X-axis is defined as the width direction of the ion exchange membrane, the Z-axis is defined as the direction orthogonal to the X-axis and the thickness direction of the ion exchange membrane, and the Y-axis is defined as the direction perpendicular to the X-axis and the Z-axis.

From a tomographic image (explanatory view shown in fig. 45)) obtained by X-ray CT measurement, the image is cut in a rectangular parallelepiped so that all image data in the thickness direction of the ion exchange membrane in a range in which 6 warps and 6 wefts are present in the core material of the ion exchange membrane are included, and all sides of the rectangular parallelepiped are parallel to any one of the X axis, the Y axis, and the Z axis of the ion exchange membrane. This is referred to as a three-dimensional image 1 (an explanatory view shown in fig. 46).

For the three-dimensional image 1, the Otsu method of the image processing method is applied to perform region segmentation. The luminance value of the pixel is set so that air is 0 and the ion exchange membrane is 255. The image thus obtained is referred to as a three-dimensional image 2 (an explanatory view shown in fig. 47). The uneven shape of the ion exchange membrane was observed using this image.

In the three-dimensional image 2, in order to evaluate the unevenness of the evaluation surface, a plane (surface 1) is determined as an arbitrary surface (an explanatory view shown in fig. 48) which is parallel to a plane created by the X axis and the Y axis of the ion exchange membrane, does not intersect the ion exchange membrane, and does not have the ion exchange membrane between itself and the evaluation surface.

As shown in the explanatory diagrams of fig. 49 and 50, a line perpendicular to the surface 1 is drawn from each pixel of the surface 1 toward the surface of the ion exchange membrane, and the length from the surface 1 to the contact with the surface of the ion exchange membrane is determined. An image having the same number of pixels as the surface 1 is defined as a surface 2, and the length obtained in the foregoing is used as the luminance value of each pixel of the surface 2 to obtain a contour map (two-dimensional image 1) of the height of the unevenness. Since the two-dimensional image 1 is an image of a distance obtained by observing the irregularities of the ion exchange membrane from the outside, the image is regarded as the irregularities of the ion exchange membrane itself, and therefore the image calculation of the following formula is performed for each pixel to obtain a two-dimensional image 2 (for example, an explanatory view shown in fig. 51).

Two-dimensional image 1 (calculated for each pixel) is a maximum value of two-dimensional image 1, i.e., two-dimensional image 2

Next, an operation of removing the inclination of the sample and the distortion of the sample at the time of X-ray CT measurement is performed. For the two-dimensional image 2, mean filtering was performed in an influence range corresponding to a radius of 300 μm to obtain a two-dimensional image 3. The two-dimensional image 4 from which the tilt and the distortion are removed is obtained by the image operation of the following expression. This was taken as an image reflecting the unevenness of the ion-exchange membrane.

Two-dimensional image 4-two-dimensional image 3

(calculation of gap volume/area)

The volume of the three-dimensional gap (the space of the oblique lines shown in fig. 51) sandwiched between the uneven surface of the ion exchange membrane and the specific plane (the surface 3 shown in fig. 51) was determined. The "specific plane" referred to herein (the face 3 shown in fig. 51) is defined as follows: which is parallel to the XY plane of the ion exchange membrane and cuts the uneven surface of the ion exchange membrane with the surface 3, the ratio of the area of the cut portion of the surface 3 (i.e., the ratio of the cross-sectional area of the cut surface of the uneven surface to the area of the entire surface 3) is 2%. That is, for the two-dimensional image 4 as information of the height of the irregularities on the surface of the ion exchange membrane, a threshold value is obtained in which the number of pixels of the brightness value equal to or higher than a certain threshold value is 2% of the total number of pixels, and the gap volume/area is obtained based on the following expression.

Gap volume/area ═ Σ (threshold value-two-dimensional image 4)/total number of pixels of two-dimensional image 4

(Σ is not a sum, for a two-dimensional image 4, it refers to summing over all pixels whose luminance values are smaller than a threshold value.)

(calculation of concave-convex information)

For the two-dimensional image 4, the maximum value and the minimum value of the height in the surface irregularity structure, the height difference which is the difference between the maximum value and the minimum value, the average value of the height differences, and the standard deviation of the height differences are obtained.

In examples 2-1 to 2-7, the ratio a on the cathode surface side (carboxylic acid layer side) of the separator was determined, and in examples 2-8, the ratio a on the anode surface side (sulfonic acid layer side) of the separator was determined.

[ method for producing electrode for electrolysis ]

(step 1)

As an electrode base material for cathode electrolysis, a nickel foil was prepared, which was subjected to a surface roughening treatment by electrolytic nickel plating on one surface thereof and had a gauge thickness of 22 μm.

(step 2)

The nickel foil was punched to form circular holes having a diameter of 1mm, thereby obtaining a porous foil. The open porosity was 44%.

(step 3)

A cathode coating liquid for forming an electrode catalyst was prepared as follows. A ruthenium nitrate solution (Furuya Metal, K.K.) having a ruthenium concentration of 100g/L and cerium nitrate (Kishida Chemical Co., Ltd.) were mixed so that the molar ratio of the ruthenium element to the cerium element was 1: 0.25. The mixture was sufficiently stirred to prepare a cathode coating solution.

(step 4)

The tray containing the above-described cathode coating liquid was set to the lowermost part of the roll coating apparatus. The cathode coating liquid was placed in contact with a coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an ethylene-propylene-diene monomer (EPDM) foam of a self-contained bubble type wound around a cylinder made of PVC (polyvinyl chloride) so as to be in constant contact with the cathode coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon. The porous foil (electrode base material) formed in step 2 was passed between the second coating roll and the uppermost PVC roll to apply the cathode coating solution (roll coating method). Thereafter, the plate was dried at 50 ℃ for 10 minutes, pre-fired at 150 ℃ for 3 minutes, and fired at 400 ℃ for 10 minutes. These operations of coating, drying, pre-firing and firing are repeated until a predetermined coating amount is reached. Thus, a cathode electrode for electrolysis was produced.

After forming the coating film, the step S_a/S_all、S_aveAnd H/t.

[ electrolytic evaluation ]

The electrolytic performance was evaluated by the following electrolytic experiment.

An anode cell made of titanium having an anode chamber provided with an anode and a cathode cell having a cathode chamber made of nickel having a cathode are opposed to each other. A pair of spacers are disposed between the cells, and an ion exchange membrane is sandwiched between the pair of spacers. Thereafter, the anode unit, the gasket, the ion exchange membrane, the gasket, and the cathode were closely attached to obtain an electrolytic unit.

As an anode, a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride was applied to a titanium substrate subjected to sandblasting and acid etching as pretreatment, and dried and fired to produce the anode. The anode is fixed to the anode chamber by welding. As the cathode, the cathode manufactured by the above-described method was used. As the current collector of the cathode chamber, a nickel metal mesh was used. The current collector had dimensions of 95mm in length by 110mm in width. As the metal elastic body, a pad woven with a nickel thin wire was used. A pad as a metal elastomer is placed on the current collector. A nickel mesh obtained by plain-weaving a nickel wire having a diameter of 150 μm with a mesh of 40 mesh was covered on the current collector, and four corners of the Ni mesh were fixed to the current collector with strings made of teflon (registered trademark). The Ni mesh was used as a power supply. In this electrolytic cell, a zero-pitch structure is formed by the repulsive force of the pad as a metal elastic body. As the gasket, a rubber gasket made of EPDM (ethylene propylene diene monomer) was used.

An anode cell made of titanium having an anode chamber provided with an anode and a cathode cell having a cathode chamber made of nickel having a cathode are opposed to each other. A pair of pads was disposed between the cells, and the laminate produced in each of examples and comparative examples was sandwiched between the pair of pads. And then the anode unit, the gasket, the ion exchange membrane, the gasket and the cathode are closely connected to obtain the electrolysis unit. The electrolytic area is 104.5cm². The ion exchange membrane was disposed so that the resin a side faced the cathode chamber.

(evaluation of the electrode for electrolysis laminated on the resin A side of the ion exchange membrane F2 (examples 2-1 to 2-6))

As the anode, a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride was applied to a titanium substrate subjected to sandblasting and acid etching as pretreatment, and dried and fired to produce an anode. The anode is fixed to the anode chamber by welding. As the current collector of the cathode chamber, a nickel metal mesh was used. The current collector had dimensions of 95mm in length by 110mm in width. As the metal elastic body, a pad woven with a nickel thin wire was used. A pad as a metal elastomer is placed on the current collector. A nickel mesh obtained by plain-weaving a nickel wire having a diameter of 150 μm with a mesh of 40 mesh was covered on the current collector, and four corners of the Ni mesh were fixed to the current collector with strings made of teflon (registered trademark). The Ni mesh was used as a power supply. In this electrolytic cell, a zero-pitch structure is formed by the repulsive force of the pad as a metal elastic body. As the gasket, a rubber gasket made of EPDM (ethylene propylene diene monomer) was used.

A porous foil was produced by punching a circular hole having a diameter of 1mm in a nickel foil having a gauge thickness of 22 μm as an electrode for electrolysis used in a laminate. The open porosity was 44%. A coating liquid for forming an electrode catalyst on the nickel foil was prepared as follows.

A ruthenium nitrate solution (Furuya Metal, K.K.) having a ruthenium concentration of 100g/L and cerium nitrate (Kishida chemical) were mixed so that the molar ratio of the ruthenium element to the cerium element was 1: 0.25. The mixture was sufficiently stirred to prepare a cathode coating solution.

The pan containing the coating liquid was set to the lowermost part of the roll coater. A coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an independent bubble type foamed EPDM (ethylene propylene diene monomer) wound around a cylinder made of PVC (polyvinyl chloride) was set so as to be always in contact with the coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon. The electrode base material was passed between the 2 nd coating roll and the uppermost PVC roll to apply the coating solution (roll coating method). Thereafter, the plate was dried at 50 ℃ for 10 minutes, pre-fired at 150 ℃ for 3 minutes, and fired at 350 ℃ for 10 minutes. This series of operations of coating, drying, pre-firing, and firing was repeated. The thickness of the prepared electrode for electrolysis was 29 μm. The thickness of the catalyst layer containing ruthenium oxide and cerium oxide was a value obtained by subtracting the thickness of the electrode base material for electrolysis from the thickness of the electrode for electrolysis, and was 7 μm, respectively.

The electrolysis of the salt is carried out using the electrolysis cell described above. The brine concentration (sodium chloride concentration) in the anode compartment was adjusted to 205 g/L. The sodium hydroxide concentration in the cathode chamber was adjusted to 32 mass%. The respective temperatures of the anode chamber and the cathode chamber were adjusted in such a manner that the temperature in each electrolysis cell was 90 ℃. At 6kA/m²The current density of (2) was measured by performing salt electrolysis, and the voltage, current efficiency, and salt concentration in sodium hydroxide were measured. The salt concentration in sodium hydroxide represents a value converted to 50% of the sodium hydroxide concentration.

(evaluation of the electrode for electrolysis laminated on the resin B side of the ion exchange membrane F2 (examples 2 to 7))

As an electrode base material for electrolysis, a titanium fiber having a thickness of 100 μm, a diameter of about 20 μm and a basis weight of 100g/m was used²And a titanium nonwoven fabric having an aperture ratio of 78%.

The coating liquid for forming the electrode catalyst was prepared as follows. A ruthenium chloride solution (Takara Shuzo Co., Ltd.) having a ruthenium concentration of 100g/L, iridium chloride (Takara Shuzo Co., Ltd.) having an iridium concentration of 100g/L, and titanium tetrachloride (Wako pure chemical industries, Ltd.) were mixed so that the molar ratio of the ruthenium element, the iridium element, and the titanium element was 0.25: 0.5. The mixed solution was sufficiently stirred to prepare an anode coating solution.

The pan containing the coating liquid was set to the lowermost part of the roll coater. A coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an independent bubble type foamed EPDM (ethylene propylene diene monomer) wound around a cylinder made of PVC (polyvinyl chloride) was set so as to be always in contact with the coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon. The electrode base material was passed between the second coating roll and the uppermost PVC roll to apply the coating solution (roll coating method). After the coating liquid was applied to the porous titanium foil, the porous titanium foil was dried at 60 ℃ for 10 minutes and baked at 475 ℃ for 10 minutes. After repeating the series of operations of coating, drying, pre-firing and firing, firing was performed at 520 ℃ for 1 hour. The thickness of the electrode was 114 μm. The thickness of the catalyst layer was 14 μm, which is the difference obtained by subtracting the thickness of the electrode base material for electrolysis from the thickness of the electrode.

The cathode was prepared as follows. First, a nickel wire mesh having a wire diameter of 150 μm and a mesh size of 40 was prepared as a base material. After sand blast treatment with alumina as a pretreatment, the plate was immersed in 6N hydrochloric acid for 5 minutes, washed thoroughly with pure water, and dried. Then, a ruthenium nitrate solution (Furuya Metal, K.K.) having a ruthenium concentration of 100g/L and cerium nitrate (Kishida Chemical Co., Ltd.) were mixed so that the molar ratio of the ruthenium element to the cerium element was 1: 0.25. The mixture was sufficiently stirred to prepare a cathode coating solution.

The pan containing the coating liquid was set to the lowermost part of the roll coater. A coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an independent bubble type foamed EPDM (ethylene propylene diene monomer) wound around a cylinder made of PVC (polyvinyl chloride) was set so as to be always in contact with the coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon. The electrode base material was passed between the second coating roll and the uppermost PVC roll to apply the coating solution (roll coating method). Thereafter, the plate was dried at 50 ℃ for 10 minutes, pre-fired at 150 ℃ for 3 minutes, and fired at 350 ℃ for 10 minutes. A series of operations of coating, drying, pre-firing, and firing are repeated. The cathode was provided in the cathode unit in place of the Ni mesh power supply.

The anode, which is deteriorated to increase the electrolytic voltage, is fixed to the anode unit by welding to serve as an anode power supply. That is, the cross-sectional structure of the cell is a zero-pitch structure in which a current collector, a mat, a cathode, a separator, an electrode for electrolysis, and an anode which is deteriorated and increases the electrolysis voltage are arranged in this order from the cathode chamber side. The anode, which is deteriorated to increase the electrolytic voltage, functions as a power supply. The electrolysis electrode and the anode deteriorated to increase the electrolysis voltage are merely in physical contact with each other and are not fixed by welding.

[ example 2-1]

The ion exchange membrane F2 was equilibrated with a 0.1mol/l aqueous solution of sodium hydroxide. The electrode for electrolysis was bonded to the resin a side of the ion-exchange membrane F2 by the surface tension of the aqueous solution adhering to the surface of the ion-exchange membrane F2 to obtain a laminate. The surface of the electrolysis electrode was set to the Ni mesh power supply side, and the electrolysis unit was assembled to perform the electrolysis evaluation.

The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F2, and S of the electrode for electrolysis_a/S_all、S_aveAnd H/t. In addition, the value M is 0.

[ examples 2-2]

In the production of an ion exchange membrane, while blowing room temperature air from the top, the membrane was heated and decompressed for 2 minutes under conditions of a plate surface temperature of 223 ℃ and a vacuum degree of 0.067 MPa. The obtained ion-exchange membrane F3 was used in the same manner as that for the ion-exchange membrane F2 except that the membrane was prepared.

The ion exchange membrane F3 was equilibrated with a 0.1mol/l aqueous solution of sodium hydroxide. The electrode for electrolysis was bonded to the resin a side of the ion-exchange membrane F3 by the surface tension of the aqueous solution adhering to the surface of the ion-exchange membrane F3 to obtain a laminate. The surface of the electrolysis electrode was set to the Ni mesh power supply side, and the electrolysis unit was assembled to perform the electrolysis evaluation.

The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F3, and S of the electrode for electrolysis_a/S_all、S_aveAnd H/t. In addition, the value M is 0.

[ examples 2 to 3]

In the production of the ion exchange membrane, release paper which is not embossed was used. The obtained ion-exchange membrane F4 was used in the same manner as that for the ion-exchange membrane F2 except that the membrane was prepared.

The ion exchange membrane F4 was equilibrated with a 0.1mol/l aqueous solution of sodium hydroxide. The electrode for electrolysis was bonded to the resin a side of the ion-exchange membrane F4 by the surface tension of the aqueous solution adhering to the surface of the ion-exchange membrane F4 to obtain a laminate. The surface of the electrolysis electrode was set to the Ni mesh power supply side, and the electrolysis unit was assembled to perform the electrolysis evaluation.

The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F4, and S of the electrode for electrolysis_a/S_all、S_aveAnd H/t. In addition, the value M is 0.

[ examples 2 to 4]

In the production of an ion exchange membrane, a release paper (embossed with a conical shape having a height of 50 μm), a membrane Y, a reinforcing material, and a membrane X, KAPTON were sequentially laminated, and the laminate was heated and decompressed at a surface temperature of 223 ℃ in a hot plate and a vacuum degree of 0.067MPa for 2 minutes, and then the release paper and the KAPTON membrane were removed to obtain a composite membrane. The obtained ion-exchange membrane F5 was used in the same manner as that for the ion-exchange membrane F2 except that the membrane was prepared.

The ion exchange membrane F5 was equilibrated with a 0.1mol/l aqueous solution of sodium hydroxide. The electrode for electrolysis was bonded to the resin a side of the ion-exchange membrane F5 by the surface tension of the aqueous solution adhering to the surface of the ion-exchange membrane F5 to obtain a laminate. The surface of the electrolysis electrode was set to the Ni mesh power supply side, and the electrolysis unit was assembled to perform the electrolysis evaluation.

The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F5, and S of the electrode for electrolysis_a/S_all、S_aveAnd H/t. In addition, the value M is 0.

[ examples 2 to 5]

As an electrode base material for cathode electrolysis, a nickel foil was prepared, which was subjected to a surface roughening treatment by electrolytic nickel plating on one surface thereof and had a gauge thickness of 22 μm.

The nickel foil was punched to form circular holes having a diameter of 1mm, thereby obtaining a porous foil. The open porosity was 44%. As shown in fig. 24 (a), a porous foil having undulations formed on the surface thereof was formed by embossing a porous foil at a linear pressure of 333N/cm using a metal roll and a resin roll having a pattern formed on the surface thereof. The metal roll was brought into contact with a surface which had not been subjected to roughening treatment, and subjected to embossing. That is, the rough surface is formed with a convex portion, and the surface not subjected to the rough surface is formed with a concave portion.

A cathode coating liquid for forming an electrode catalyst was prepared as follows. A ruthenium nitrate solution (Furuya Metal, K.K.) having a ruthenium concentration of 100g/L and cerium nitrate (Kishida Chemical Co., Ltd.) were mixed so that the molar ratio of the ruthenium element to the cerium element was 1: 0.25. The mixture was sufficiently stirred to prepare a cathode coating solution.

The tray containing the above-described cathode coating liquid was set to the lowermost part of the roll coating apparatus. The cathode coating liquid was placed in contact with a coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an ethylene-propylene-diene monomer (EPDM) foam of a self-contained bubble type wound around a cylinder made of PVC (polyvinyl chloride) so as to be in constant contact with the cathode coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon. The porous foil (electrode base material) formed in step 2 was passed between the second coating roll and the uppermost PVC roll to apply the cathode coating solution (roll coating method). Thereafter, the mixture was dried at 50 ℃ for 10 minutes, pre-fired at 150 ℃ for 3 minutes, and fired at 400 ℃ for 10 minutes. The series of operations of coating, drying, pre-firing and firing are repeated until a predetermined coating amount is reached. Thus, a cathode electrode for electrolysis (130 mm. times.130 mm. times.t 28 μm thick) having a coating layer (catalyst layer) on the electrode substrate for electrolysis was produced. FIG. 24 (B) is a schematic view showing a part of the surface of the electrolysis electrode of examples 2 to 5. As can be seen from this figure, the undulation corresponding to the metal roll is formed in the portion other than the opening portion of the electrode for electrolysis. Further, regions in which the undulation portions are independently arranged are observed in at least one direction in the facing surfaces of the electrodes for electrolysis.

S was measured by the method described later using the electrode for electrolysis as an object_a/S_all、S_aveAnd H/t. Further also for M (═ S)_a/S_all×S_aveXH/t) was 0.131.

Then, using the ion-exchange membrane F3 used in example 2-2 as an ion-exchange membrane, the surface of the electrolysis electrode on which the projections were formed was opposed to the resin a side of the ion-exchange membrane F3, to obtain a laminate. The surface of the electrolysis electrode was set to the Ni mesh power supply side, and the electrolysis unit was assembled to perform the electrolysis evaluation. The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F3, and S of the electrode for electrolysis_a/S_all、S_ave、H/t。

[ examples 2 to 6]

A laminate was obtained in the same manner as in examples 2 to 5, except that the ion-exchange membrane F5 used in examples 2 to 4 was used as the ion-exchange membrane. That is, the surface of the electrolysis electrode exhibiting the convex portion was opposed to the resin a side of the ion exchange membrane F5 to obtain a laminate. The surface of the electrolysis electrode was set to the Ni mesh power supply side, and the electrolysis unit was assembled to perform the electrolysis evaluation. The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F5, and S of the electrode for electrolysis _a/S_all、S_aveAnd H/t. In addition, the value M was 0.131.

[ examples 2 to 7]

The ion exchange membrane F2 was equilibrated with a 0.1mol/l aqueous solution of sodium hydroxide. An electrode for electrolysis using a titanium nonwoven fabric was bonded to the resin B side of the ion-exchange membrane F2 by the surface tension of the aqueous solution adhering to the surface of the ion-exchange membrane F2, to obtain a laminate. The surface of the electrolysis electrode was set to the anode current-supplying body side, and the unit was assembled to the electrolysis cell to conduct the electrolysis evaluation. The results are shown in Table 2.

Also shown in Table 2 are the interstitial volume/area (ratio a), height difference, standard deviation, interfacial water content w of the ion-exchange membrane F5, and S of the electrode for electrolysis_a/S_all、S_aveAnd H/t. In addition, the value M is 0.

Comparative example 2-1

In comparative example 2-1, a membrane electrode assembly in which electrodes were thermocompression bonded to a separator was prepared with reference to the prior art document (example of jp 58-48686 a).

As an electrode substrate for cathode electrolysis, electrode coating was carried out in the same manner as in example 2-1 using a nickel metal lath having a gauge thickness of 100 μm and an opening ratio of 33%. Thereafter, one surface of the electrode was subjected to an inert treatment by the following procedure. A polyimide tape (Zhongxing chemical Co., Ltd.) was attached to one surface of the electrode, and a PTFE dispersion (31-JR, Mitsui Dupont fluorochemicals) was applied to the opposite surface, followed by drying in a muffle furnace at 120 ℃ for 10 minutes. The polyimide tape was peeled off, and the polyimide tape was subjected to a sintering treatment in a muffle furnace set at 380 ℃ for 10 minutes. This operation was repeated 2 times, and one surface of the electrode was inerted.

Prepared by reacting a terminal functional group of-COOCH₃"perfluorocarbon polymer (C polymer) and having end group of" -SO₂F' (ii) a 2-layer formed membrane of a perfluorocarbon polymer (S polymer). The thickness of the C polymer layer was 3 mils (mil) and the thickness of the S polymer layer was 4 mils (mil). The 2-layer membrane was subjected to saponification treatment, and an ion exchange group was introduced into the terminal of the hydrolyzed polymer. That is, the C polymer end is hydrolyzed to a carboxylic acid group, and the S polymer end is hydrolyzed to a sulfo group. The ion exchange capacity was 1.0meq/g for the sulfonic acid group and 0.9meq/g for the carboxylic acid group.

The surface of the inert electrode is placed opposite to the surface having a carboxylic acid group as an ion exchange group, and hot pressing is performed to integrate the ion exchange membrane and the electrode. After thermocompression bonding, one surface of the electrode is exposed, and there is no portion where the electrode penetrates the film.

Thereafter, in order to suppress the adhesion of bubbles generated during electrolysis to the membrane, a mixture of zirconia and a perfluorocarbon polymer having sulfonic groups introduced thereto was applied to both sides. Thus, a membrane electrode assembly of comparative example 2-1 was produced.

The separator used in the laminate of comparative example 2-1 was formed into a flat surface. Since the electrodes are connected by thermocompression bonding, the interfacial water content w is 0.

Electrolytic evaluation was carried out, and as a result, electrolytic performance was significantly deteriorated (table 2). In addition, the value M is 0.

(method of measuring Each parameter)

(S_aCalculating method of (1)

The surface of the electrode for electrolysis (the surface on the coating layer side described later) was observed with an optical microscope (digital microscope) at a magnification of 40 times, and the total area S of the undulation portion of the surface of the electrode for electrolysis was calculated_a. The calculated value was calculated by averaging the values of 5 visual fields, 1 visual field being 7.7mm × 5.7 mm.

(S_allCalculating method of (1)

The surface of the electrode for electrolysis (the surface on the coating layer side described later) was observed with an optical microscope at a magnification of 40 times, and the area of the opening portion in the entire observation field was subtracted from the area of the entire observation field, thereby calculating the area. The calculated value was calculated by averaging the values of 5 visual fields, 1 visual field being 7.7mm × 5.7 mm.

(S_aveCalculating method of (1)

The surface of the electrode for electrolysis (the surface on the coating layer side described later) was observed with an optical microscope at a magnification of 40 times. From the observation image, an image was prepared by blacking only the undulation on the surface of the electrode for electrolysis. That is, the image to be created is an image showing only the shape of the undulating portion. The areas of the independent undulations were calculated from the 50 regions in the image pair, and the average value was S _ave. Note that 1 field of view is 7.7mm × 5.7mm, and when the number of independent undulations is less than 50, the additional observation field of view is added.

When the relief portion is observed using an optical microscope, shadows due to the relief by the irradiation light are observed. The center of the shadow is defined as the boundary line between the undulating portion and the flat portion. For a sample in which shading is difficult to occur, shading occurs by tilting the angle of the light source extremely slightly. S_aveIs to make the unit be mm²And calculated.

(method of measuring H, h and t)

The following H, h and t were determined by the methods described below.

h: average of height of convex part or depth of concave part

t: average value of thickness of electrode itself

H：h+t

The section of the electrode for electrolysis was observed with a scanning electron microscope (manufactured by S4800 hitachi high and new technologies) and the thickness of the electrode was determined by length measurement. The observation sample was prepared by embedding the electrolysis electrode with a resin and then exposing the cross section by mechanical polishing. The thickness of the electrode portion was measured at 6 sites, and the average value thereof was taken as t.

With respect to H, the substrate after the embossing was subjected to catalyst coating, and the entire surface area of the produced electrode was measured at 10 points by a digital display thickness gauge (Mitutoyo, ltd., minimum display 0.001mm) so as to include the embossed portion, and the average value thereof was defined as H.

For H, t is subtracted from H to calculate (H ═ H-t).

< verification of embodiment 3 >

As described below, experimental examples corresponding to embodiment 3 (hereinafter, simply referred to as "examples" in the term of < verification of embodiment 3 >) and experimental examples not corresponding to embodiment 3 (hereinafter, simply referred to as "comparative examples" in the term of < verification of embodiment 3 >) were prepared and evaluated by the following methods.

(production of electrode for cathode Electrolysis)

As an electrode base material, a nickel foil having a thickness of 22 μm, a length of 95mm and a width of 110mm was prepared. One surface of the nickel foil is subjected to a surface roughening treatment by electrolytic nickel plating. The arithmetic average roughness Ra of the roughened surface was 0.71. mu.m. The surface roughness was measured by using a stylus-type surface roughness meter SJ-310 (Mitutoyo Co., Ltd.). That is, the measurement sample was set on a surface plate parallel to the ground, and the arithmetic average roughness Ra was measured under the following measurement conditions. In the measurement, when 6 times of the measurement were carried out, the average value thereof was recorded.

< shape of contact pin > cone angle 60 °, tip radius 2 μm, and static measurement force 0.75mN

< roughness standard > JIS2001

< evaluation Curve > R

< Filter > GAUSS

< cut-off wavelength value λ c >0.8mm

< cut-off wavelength value λ s >2.5 μm

< number of intervals >5

< front walk, rear walk > have

The nickel foil was punched to form circular holes, thereby forming a porous foil. The open pore ratio calculated as follows was 44%.

(measurement of open porosity)

The electrode for electrolysis was uniformly measured at 10 points in the plane using a digital thickness meter (manufactured by Mitutoyo corporation, minimum display 0.001mm), and the average value was calculated. The volume was calculated by using the thickness of the electrode (gauge thickness). Thereafter, the mass was measured by an electronic balance, and the specific gravity of the metal (specific gravity of nickel: 8.908 g/cm)³Specific gravity of titanium is 4.506g/cm³) And calculating the opening rate or the void ratio.

Open pore ratio (porosity) (%) (1- (electrode mass)/(electrode volume × specific gravity of metal)) × 100

The coating liquid for forming the electrode catalyst was prepared as follows. A ruthenium nitrate solution (Furuya Metal, K.K.) having a ruthenium concentration of 100g/L and cerium nitrate (Kishida chemical) were mixed so that the molar ratio of the ruthenium element to the cerium element was 1: 0.25. The mixture was sufficiently stirred to prepare a cathode coating solution.

The pan containing the coating liquid was set to the lowermost part of the roll coater. A coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an independent bubble type foamed EPDM (ethylene propylene diene monomer) wound around a cylinder made of PVC (polyvinyl chloride) was set so as to be always in contact with the coating liquid. An applicator roll was provided on the upper part thereof, around which EPDM was also wound, and a PVC roll was further provided thereon. The electrode base material was passed between the second coating roll and the uppermost PVC roll to apply the coating solution (roll coating method). Thereafter, the plate was dried at 50 ℃ for 10 minutes, pre-fired at 150 ℃ for 3 minutes, and fired at 350 ℃ for 10 minutes. The series of operations of coating, drying, pre-firing and firing are repeated until a predetermined coating amount is reached. The thickness of the thus-obtained electrode for electrolysis (length 95mm, width 110mm) was 28 μm. The thickness of the catalyst layer (total thickness of ruthenium oxide and cerium oxide) was 6 μm, which is the difference obtained by subtracting the thickness of the electrode base material for electrolysis from the thickness of the electrode. The catalyst layer was also formed on the surface not roughened.

(production of electrode for Anode electrolysis)

As an electrode base material for anode electrolysis, a material having a gauge thickness of 100 μm, a titanium fiber diameter of about 20 μm and a basis weight of 100g/m was used²And a titanium nonwoven fabric having an aperture ratio of 78%.

The coating liquid for forming the electrode catalyst was prepared as follows. A ruthenium chloride solution (Takara Shuzo Co., Ltd.) having a ruthenium concentration of 100g/L, iridium chloride (Takara Shuzo Co., Ltd.) having an iridium concentration of 100g/L, and titanium tetrachloride (Wako pure chemical industries, Ltd.) were mixed so that the molar ratio of the ruthenium element, the iridium element, and the titanium element was 0.25: 0.5. The mixed solution was sufficiently stirred to prepare an anode coating solution.

The pan containing the coating liquid was set to the lowermost part of the roll coater. A coating roller having a rubber (Inoac Corporation, E-4088, thickness 10mm) made of an independent bubble type foamed EPDM (ethylene propylene diene monomer) wound around a cylinder made of PVC (polyvinyl chloride) was set so as to be always in contact with the coating liquid. A coating roll wound with the same EPDM was provided on the upper part of the roll, and a PVC roll was further provided thereon. The electrode base material was passed between the second coating roll and the uppermost PVC roll to apply the coating solution (roll coating method). After the coating liquid was applied to the porous titanium foil, the porous titanium foil was dried at 60 ℃ for 10 minutes and baked at 475 ℃ for 10 minutes. After repeating the series of operations of coating, drying, pre-firing and firing, firing was performed at 520 ℃ for 1 hour. The thickness of the obtained electrode for anodic electrolysis (length 95mm, width 110mm) was 114. mu.m.

< ion exchange Membrane >

As the separator, an ion exchange membrane a manufactured as follows was used.

As the reinforcing core material, a Polytetrafluoroethylene (PTFE) monofilament of 90 denier (hereinafter referred to as PTFE yarn) was used. As the sacrificial yarn, yarn obtained by twisting polyethylene terephthalate (PET) of 35 denier and 6 filaments at 200 times/m (hereinafter referred to as PET yarn) was used. First, in both TD and MD directions, a woven fabric was obtained by plain-weaving PTFE filaments at 24 filaments/inch and sacrificial filaments arranged at 2 filaments between adjacent PTFE filaments. The obtained woven fabric was pressed against a roller to obtain a reinforcing material as a woven fabric having a thickness of 70 μm.

Next, resin A (which is CF) which is a dried resin having an ion exchange capacity of 0.85mg equivalent/g was prepared₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOCH₃Copolymer of (B), resin B (which is CF) which is a dry resin having an ion exchange capacity of 1.03mg equivalent/g₂＝CF₂And CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂Copolymers of F).

Using these resin A and resin B, a 2-layer film X having a resin A layer thickness of 15 μm and a resin B layer thickness of 84 μm was obtained by a coextrusion T-die method. A single-layer film Y having a thickness of 20 μm was obtained by the T-die method using only the resin B.

Subsequently, a release paper (conical embossing having a height of 50 μm), a film Y, a reinforcing material, and a film X were sequentially laminated on a hot plate having a heating source and a vacuum source inside and having fine holes on the surface thereof, and the release paper was removed after heating and pressure reduction for 2 minutes under conditions of a hot plate surface temperature of 223 ℃ and a vacuum degree of 0.067MPa, thereby obtaining a composite film. The film X is laminated in the following manner with the resin B.

The obtained composite membrane was immersed in an aqueous solution containing 30 mass% of dimethyl sulfoxide (DMSO) and 15 mass% of potassium hydroxide (KOH) at 80 ℃ for 20 minutes, thereby performing saponification. Thereafter, the substrate was immersed in an aqueous solution containing sodium hydroxide (NaOH)0.5N at 50 ℃ for 1 hour to replace the counter ion of the ion exchange group with Na, followed by water washing. Thereafter, the surface of the side of the resin B was polished at a relative speed of 100 m/min and a pressing amount of 2mm to form an opening portion, and then dried at 60 ℃.

Further, 20 mass% of zirconia having a 1-order particle diameter of 1 μm was added to a 5 mass% ethanol solution of an acid resin of resin B, and dispersed to prepare a suspension, and the suspension was sprayed on both surfaces of the composite film by a suspension spraying method to form a zirconia coating layer on the surface of the composite film, thereby obtaining an ion exchange membrane a as a separator.

The coating density of zirconia was measured by fluorescent X-ray measurement, and found to be 0.5mg/cm². Here, the average particle diameter was measured by a particle size distribution meter ("SALD (registered trademark) 2200", manufactured by shimadzu corporation).

(example 3-1) case where the separator was not replaced

As shown in fig. 28, an electrolytic cell was produced. First, a titanium anode frame having an anode chamber provided with an anode and a nickel cathode frame having a cathode chamber provided with a cathode were opposed to each other. The external dimensions of the anode frame and the cathode frame are 150mm in length and 150mm in width. A pair of spacers are disposed between the cells, and an ion exchange membrane is sandwiched between the pair of spacers. And then the anode unit, the gasket, the ion exchange membrane, the gasket and the cathode are tightly combined, and are clamped by a stainless steel plate with a bolt hole in advance, and the electrolytic unit is fixed by fastening a bolt. The electrolytic cells are formed by connecting a plurality of electrolytic cell frames in series as a set of electrolytic cell frames. That is, the cathode frames of the adjacent electrolytic cell frames are connected to the back surface side of the anode frame of one pair of electrolytic cell frames.

As an anode, the same electrode base material for electrolysis was subjected to sandblasting and acid etching as described above as a pretreatment, and a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride was applied to the obtained titanium base material in the same manner as in the above-described "production of an electrode for electrolysis, followed by drying and firing to produce the anode. The anode is fixed to the anode chamber by welding.

As the current collector of the cathode chamber, a nickel metal mesh was used. The current collector had dimensions of 95mm in length by 110mm in width.

As the metal elastic body, a pad woven with a nickel thin wire was used.

A pad as a metal elastomer is placed on the current collector.

As the cathode, similarly to the above-mentioned "preparation of an electrode for cathodic electrolysis", an electrode obtained by coating ruthenium oxide and cerium oxide on a nickel mesh obtained by plain-weaving a nickel wire having a diameter of 150 μm with a mesh of 40 mesh was used, and the resultant was subjected to electrolysis for 8 years (electrolysis conditions: current density: 6.2 kA/m)²And a brine concentration of 3.2 to 3.7mol/l, a caustic alkali concentration of 31 to 33%, and a temperature of 80 to 88 ℃ are the same as electrolysis conditions described later). That is, the four corners are fixed to the current collector by a string made of teflon (registered trademark). Since the coating was used for 8 years, the coating amounts of ruthenium oxide and cerium oxide were about 1/10 of the values when they were not used.

Further, as the ion exchange membrane, ion exchange membrane A was used for 4 years of electrolysis (electrolysis condition: current density 6.2 kA/m)²And a brine concentration of 3.2 to 3.7mol/l, a caustic alkali concentration of 31 to 33%, and a temperature of 80 to 88 ℃ are the same as the electrolysis conditions described later).

In this electrolytic cell, the zero-pitch structure is achieved by the repulsive force of the metal elastic body pad. As the gasket, a rubber gasket made of EPDM (ethylene propylene diene monomer) was used.

The electrolysis of common salt before the refreshing operation was carried out using the above electrolysis cell. The brine concentration (sodium chloride concentration) in the anode compartment was adjusted to 3.5 mol/l. The sodium hydroxide concentration in the cathode chamber was adjusted to 32 mass%. The respective temperatures of the anode chamber and the cathode chamber were adjusted in such a manner that the temperature in each electrolysis cell was 90 ℃. At 6kA/m²The current density of (2) was measured by salt electrolysis and the voltage and current efficiency were measured. Here, the current efficiency is a ratio of the amount of the generated sodium hydroxide to the flowing current, and if impurity ions or hydroxide ions other than sodium ions are moved in the ion exchange membrane by the flowing current, the current efficiency is lowered. The current efficiency was determined by dividing the number of moles of sodium hydroxide generated over a given period of time by the number of moles of electrons in the current flowing therebetween. The number of moles of sodium hydroxide was determined by recovering sodium hydroxide produced by electrolysis into a plastic tank and measuring the mass thereof. As the cathode electrode, a cathode whose coating amount is significantly reduced over a long period of time is used, and thus the voltage is increased. The voltage was as high as 3.20V, as opposed to 3.02V when a new cathode was used, and the current efficiency was as low as 95.3%.

After the electrolysis is stopped and the anode chamber and the cathode chamber are washed with water, the bolts are loosened from the state shown in fig. 32 (a), and the anode frame and the cathode frame are released from integration, so that the cathode surface side of the ion exchange membrane is exposed as shown in fig. 32 (B) (step (a 1)). In the state shown in fig. 32 (B), the ion-exchange membrane was wetted with a 0.1mol/L NaOH aqueous solution, and then the cathode electrolysis electrode produced in the above-described step was disposed on the exposed surface of the ion-exchange membrane, so as to be in the state shown in fig. 32 (C) (step (B1)). Here, the angle between the horizontal plane and the mounting plane of the cathode electrode for cathode electrolysis relative to the ion exchange membrane was 0 °. The anode frame and the cathode frame are integrated again from the state shown in fig. 32 (C), and the anode, the cathode, the ion exchange membrane, and the cathode electrode for electrolysis are accommodated in the electrolysis cell frame to be in the state shown in fig. 32 (D) (step (C1)).

Using the thus-assembled electrolysis cell, salt electrolysis was carried out again under the same conditions as described above, and the voltage was 2.96V. The electrolytic performance is improved by a simple operation.

Further, immediately before the step C1, the cathode electrolysis electrode was taken out, and the weight (E) in the state where moisture was adhered was measured by the following method.

< measurement of the amount of Water adhering to the electrode for electrolysis >

The electrodes for electrolysis of each example were stored in a dryer at 50 ℃ for 30 minutes or more and dried, and then weighed. This operation was performed 5 times, and an average value was obtained. The value obtained by dividing this value by the outer dimension area of the electrode for electrolysis was defined as e (g/m)²). Next, immediately before the step (C1) or the step (C2), one end of each of the four corners of the electrolysis electrode laminated on the ion exchange membrane was lifted, and the electrolysis electrode was peeled off from the ion exchange membrane and suspended in the air for 20 seconds, thereby removing the naturally dropped moisture. Weighing was carried out immediately after 20 seconds. This operation was performed 5 times, and an average value was obtained. This value was divided by the outer dimension area of the electrode, and the obtained value was defined as E (g/m)²). The operation is carried out in an environment with the temperature of 20-30 ℃ and the humidity of 30-50%. Assuming that the opening ratio of the electrode for electrolysis is P, the amount of water adhered per unit area (hereinafter also simply referred to as "adhered water content") W (g/m) of the aqueous solution adhered to the electrode for electrolysis is determined by the following equation²)。

W＝(E-e)/(1－P/100)

The electrolytic electrode of example 3-1 had an attached water content W of 58g/m based on the dry weight e and the opening ratio measured in advance ²。

Example 3-2 case where the separator and the cathode were replaced

The salt electrolysis before the refreshing operation was carried out in the same manner as in example 3-1, and the voltage in the salt electrolysis was 3.18V, the current efficiency was 95%, and the performance was poor.

After the electrolysis cell was stopped and the anode chamber and the cathode chamber were washed with water, the integration of the anode frame and the cathode frame was released from the state shown in fig. 32 (a) in the same manner as in example 1, and the ion exchange membrane was exposed as shown in fig. 33 (a) (step (a 2)). Next, the ion-exchange membrane was removed in the state shown in fig. 33 (B), an ion-exchange membrane having the same composition and shape as the removed ion-exchange membrane but not used was further disposed on the anode, and the same cathode electrolysis electrode as in example 3-1 was disposed so as to be in contact with the cathode surface side of the ion-exchange membrane (step (B2)). Here, the angle between the horizontal plane and the mounting plane of the cathode electrode for cathode electrolysis relative to the ion exchange membrane was 0 °. The anode frame and the cathode frame are integrated again from the state shown in fig. 33C, and the anode, the cathode, the ion exchange membrane, and the cathode electrode for electrolysis are accommodated in the electrolysis cell frame to be in the state shown in fig. 33D (step C2).

Further, immediately before the step C2, the cathode electrolysis electrode was taken out, and the weight (E) in a state where moisture was adhered was measured. The water content W of the electrode for electrolysis was 55g/m based on the dry weight e and the open pore ratio measured in advance²。

By using the thus assembled electrolysis cell and again performing electrolysis of common salt, the voltage was 2.96V, the current efficiency was 97%, and the performance was improved. The electrolytic performance is improved by a simple operation.

(example 3-3) case where the diaphragm and the anode were replaced

An electrolysis cell frame was formed and salt electrolysis was carried out in the same manner as in example 3-1, except for the following points. That is, as an anode, a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride was applied to a titanium substrate subjected to sandblasting and acid etching as pretreatment, dried and fired, and the anode thus produced was subjected to electrolysis for 8 years (electrolysis conditions: current density 6.2 kA/m)²The obtained anode is used under the same electrolysis conditions as described later except that the brine concentration is 3.2 to 3.7mol/l, the caustic alkali concentration is 31 to 33%, and the temperature is 80 to 88 ℃. On the other hand, as the cathode, an electrode obtained by coating ruthenium oxide and cerium oxide on a nickel mesh obtained by plain-weaving a nickel wire having a diameter of 150 μm with a mesh of 40 mesh was used in the same manner as in the above-described "production of an electrode for cathode electrolysis". Except that a deteriorated anode and a non-deteriorated cathode are used as such Except that an electrolysis cell was prepared in the same manner as in example 3-1 and then subjected to salt electrolysis in the same manner as described above, the voltage was 3.18V, the current efficiency was 95%, and the performance was poor.

After the electrolysis cell was stopped and the anode chamber and the cathode chamber were washed with water, the integration of the anode frame and the cathode frame was released from the state shown in fig. 32 (a) in the same manner as in example 3-1, and the ion exchange membrane was exposed as shown in fig. 33 (a 2). Next, the ion exchange membrane is removed from the state shown in fig. 33 a to bring the state shown in fig. 33B, the above-mentioned electrode for anode electrolysis is disposed on the anode from the state shown in fig. 33B, and an ion exchange membrane having the same composition and shape as the removed ion exchange membrane but not used is disposed on the anode (step (B2)). Here, the angle between the anode electrode for electrolysis and the horizontal plane with respect to the mounting surface of the ion exchange membrane was 0 °. The anode frame and the cathode frame are integrated again from the state shown in fig. 33C, and the anode, the cathode, the ion exchange membrane, and the anode electrolysis electrode are accommodated in the electrolysis cell frame to be in the state shown in fig. 33D (step C2).

Immediately before the step C2, the cathode electrolysis electrode was removed, and the weight (E) of the water adhered to the electrode was measured. The water content W of the electrolytic electrode was 358g/m based on the dry weight e and the opening ratio measured in advance ²。

The electrolysis of common salt was performed again using the thus assembled electrolysis cell, and as a result, the voltage was 2.97V and the current efficiency was 97%. The electrolytic performance is improved by a simple operation.

Example 3-4 cases where the separator, cathode, and anode were replaced

Salt electrolysis before the refresh operation was performed in the same manner as in example 3-1 except that the cathode used in example 3-1 and the ion-exchange membrane used in 4 years and the anode used in example 3-3 and the anode used in 8 years were used, respectively, in example 3-4. The salt electrolysis performance was poor at a voltage of 3.38V and a current efficiency of 95%.

After the electrolysis cell was stopped and the anode chamber and the cathode chamber were washed with water, the integration of the anode frame and the cathode frame was released from the state shown in fig. 32 (a) in the same manner as in example 3-1, and the ion exchange membrane was exposed as shown in fig. 33 (a) (step (a 2)). Next, the ion exchange membrane was removed from the state shown in fig. 33 (a) to obtain the state shown in fig. 33 (B), and the above-mentioned electrode for anode electrolysis was disposed on the anode from the state shown in fig. 33 (B), and further an ion exchange membrane having the same composition and shape as the removed ion exchange membrane but not used was disposed on the anode, and further an electrode for cathode electrolysis as in example 3-1 was disposed (step (B2)). Here, the angle between the horizontal plane and the placement plane of the cathode electrolysis electrode and the anode electrolysis electrode with respect to the ion exchange membrane was 0 °. The anode frame and the cathode frame are integrated again, and the anode, the cathode, the ion exchange membrane, the anode electrolysis electrode, and the cathode electrolysis electrode are housed in the electrolysis cell frame (step (C2)).

Further, immediately before the step C2, the cathode and the anode electrodes for electrolysis were taken out, and the weight (E) in the state where moisture was adhered was measured. The cathode contained 57g/m of the amount W of the water adhered to the electrode for electrolysis based on the dry weight e and the opening ratio measured in advance²The anode was 355g/m²。

The electrolysis of common salt was performed again using the thus assembled electrolysis cell, and as a result, the voltage was 2.97V and the current efficiency was 97%. The electrolytic performance is improved by a simple operation.

Comparative example 3-1

(original electrode renewal)

After the salt electrolysis before the refresh operation was performed in the same manner as in example 3-1, the operation was stopped and the electrolysis cell was transported to a workshop where welding work can be performed.

After the conveyance, the bolts of the electrolysis unit were loosened to release the integration of the anode frame and the cathode frame, and the ion exchange membrane was removed. Next, the anode fixed to the anode frame of the electrolytic cell by welding is peeled off and then the peeled off portion is ground and smoothed by a grinder or the like. The cathode is removed from a portion of the cathode that is woven into the current collector and fixed, and the cathode is removed.

New anodes are then placed on the ribs of the anode chamber and fixed to the electrolysis cell by spot welding. Similarly, a new cathode is provided on the cathode side, and is sandwiched and fixed between the current collectors.

The renewed electrolysis unit is transported to the site of the large-sized electrolysis tank, and the electrolysis unit is returned to the electrolysis tank by a crane.

The time required from releasing the fixing state of the electrolysis unit and the ion exchange membrane to fixing the electrolysis unit again is 1 day or more.

< contact pressure >

In the operations of examples 3-1 to 3-4, there was a possibility that wrinkles were slightly generated when the ion exchange membrane was disposed, and the wrinkles were unfolded by hand or a resin roll. Specifically, in the step (B2), pressure-sensitive paper (fuji film Prescale) is placed on the wrinkled portion of the ion exchange membrane, and the applied pressure is measured. In the case of the ion exchange membrane, it could not be measured even by using a pressure sensitive paper for ultra-low pressure (5LW), and it was 60gf/cm²The following.

In the operations of examples 3-1 to 3-4, there was a possibility that wrinkles were slightly generated when the electrolysis electrode was installed, and the wrinkles were developed by using a hand or a resin roller. Specifically, in the case of performing the steps (B1, B2), pressure-sensitive paper (Fuji film Prescale) was placed on the wrinkled portion of the electrolysis electrode, and the applied pressure was measured, whereby the pressure was 510gf/cm²The following.

The present application is based on japanese patent applications (japanese patent application No. 2018-177213, 2018-177415 and 2018-177375) filed on 21.9.2018 and japanese patent application No. 2019-120095 filed on 27.6.2019, the contents of which are incorporated in the present specification by reference.

Description of the symbols

(view corresponding to embodiment 1)

Description of the symbols of FIG. 1

100 … electrode roll, 101 … electrolysis electrode, 200 … diaphragm roll, 201 … diaphragm, 300 … polyvinyl chloride tube

Description of the symbols in FIGS. 2-3

100 … electrode roll, 101 … electrolysis electrode, 200 … diaphragm roll, 201 … diaphragm, 450 … water retention unit, 451 … water content, 452 … sponge roll

Description of the symbols in FIGS. 4-6

100 … electrode roll, 101 … electrolysis electrode, 110 … laminate, 150 … laminate manufacturing jig, 200 … diaphragm roll, 201 … diaphragm, 400 … positioning unit, 401a and 401b … pressing plate, 402 … spring mechanism, 403a and 403b … bearing portion, 450 … water retention unit, 451 … water content, 150 … water content,

Description of the symbols of FIG. 7

101 … electrode for electrolysis, 302 … guide roller

Description of symbols for FIG. 8

101 … electrode for electrolysis, 302 … guide roller

Description of symbols of FIG. 9

110 … laminate, 301 … roll

Description of symbols of FIG. 10

10 … electrolytic electrode substrate, 20 … coated substrate first layer, 30 … second layer, 101 … electrolytic electrode

Description of symbols of FIG. 11

1 … ion exchange membrane, 1a … membrane main body, 2 … carboxylic acid layer, 3 … sulfonic acid layer, 4 … reinforced core material, 11a,11b … coating layer

Description of symbols of FIG. 12

21a,21b … reinforced core material

Description of symbols (A) and (B) in FIG. 13

52 … reinforcing wire, 504 … communication hole, 504a … sacrificial wire

Description of reference numerals in fig. 14 to 18

4 … electrolyzer, 5 … pressurizer, 6 … cathode terminal, 7 … anode terminal

11 … anode, 12 … anode pad, 13 … cathode pad

18 … reverse current absorber, 18a … base material, 18b … reverse current absorbing layer, and 19 … bottom of anode cell

21 … cathode, 22 … metal elastomer, 23 … current collector and 24 … support

50 … electrolysis unit, 60 … anode chamber, 51 … ion exchange membrane (diaphragm), 70 … cathode chamber

80 … partition wall, 90 … cathode structure for electrolysis

(view corresponding to embodiment 2)

Description of symbols in FIGS. 19 to 23

101A, 101B, 101C … electrodes for electrolysis, 102A, 102B, 102C … undulations, 103A, 103B … flat portions

(view corresponding to embodiment 3)

Description of symbols in FIGS. 28 to 33

4 … electrolytic cell, 5 … pressurizer, 6 … cathode terminal, 7 … anode terminal,

11 … anode, 12 … anode pad, 13 … cathode pad,

18 … reverse current absorber, 18a … base material, 18b … reverse current absorbing layer, 19 … bottom of anode chamber,

21 … cathode, 22 … metal elastomer, 23 … current collector, 24 … anode frame, 25 … cathode frame,

50 … electrolytic cell, 60 … anode chamber, 51 … ion exchange membrane (diaphragm), electrode mounting surface for electrolysis on 51a … ion exchange membrane, 70 … cathode chamber, 101 … electrode for electrolysis, 103 … table, and electrolytic cell mounting surface on 103a … table