Cation-exchange fluorinated membrane for electrolysis and method of making said membrane

FIELD: chemistry.

SUBSTANCE: cation-exchange membrane for electrolysis which includes a fluoropolymer which contains an ion-exchange group and a porous base is distinguished by that, on the surface of the anode side of the membrane there are projecting parts with a fluorine-containing polymer which contains an ion-exchange group; 20≤h≤150, where h is the average height (mcm) from the surface of the anode side of the membrane to the top of the projecting parts; 50≤P≤1200, where P is distribution density (number/cm2) of the projecting parts; 0.001≤S≤0.6, where S is the ratio of area of the bottom surfaces of the projecting parts to the total area of the anode side of the membrane; and T≤0.05, where T is the ratio of the area of the top parts of the projecting parts to the total area of the anode side of the membrane.

EFFECT: invention enables obtaining a membrane with stable operational characteristics with retention of electrochemical properties and mechanical strength.

9 cl, 1 tbl, 7 ex

 

The technical FIELD

The invention relates to a cation exchange membrane for electrolysis, more specifically, to a cation exchange membrane for electrolysis, used for electrolysis of an aqueous solution of alkali chloride, with a stable performance with preservation of the electrochemical properties and mechanical strength and can improve the quality by reducing the content of impurities, especially alkali hydroxide, the resulting ion exchange, and also relates to a method for producing such a membrane.

The LEVEL of INVENTION

Since the fluorine-containing ion exchange membrane has high temperature resistance and chemical resistance, it is used for various purposes, such as ion-exchange membrane for electrolysis, used to obtain chlorine and alkali hydroxide by the electrolysis of alkali chloride, and the barrier membrane for electrolysis, including ozone, fuel cell, water electrolysis and electrolysis of hydrochloric acid, while it is growing.

Among the above-mentioned applications of the method using ion-exchange membranes in recent times is the most popular method of obtaining chlorine and alkali hydroxide by the electrolysis of alkali chloride. Used here jonoob the fair membrane is required not only to obtain a high utilization rate of the current, low voltage electrolysis and adequate strength of the membrane to prevent damage during electrolysis, but also to reduce the concentration of impurities, especially alkali chlorides contained in the resulting alkaline hydroxide. To meet such requirements options were offered. It is widely known that currently focuses on the use of a fluoride ion-exchange membrane having a multi-layered structure including a layer containing fluorine-containing resin containing a carboxylic acid group with a high electric resistance, but with a high utilization factor of the current, and the layer containing fluorine-containing resin containing a sulfonic group with low electric resistance, because such use is beneficial.

In addition, despite various proposals for reducing the electrical resistance by increasing the water content in the membrane, the decrease an electrical resistance by increasing the ion exchange capacity of the layer containing the carboxylic acid group causes a decrease of the utilization of current and, at the same time, the increase in the content of impurities in the alkali hydroxide. The decrease in electrical resistance by increasing the ion-exchange SP is the ability of the layer, contains the group of sulfonic acids, causes an increase in the content of impurities in the resulting alkaline hydroxide and, in addition, a marked decrease in the strength of the membrane.

As described in Patent documents 1 and 2, recently attempts are being made to reduce the voltage electrolysis and improve the strength of the membrane by increasing the number of layers in the membrane and maintaining a certain water content in each layer. However, in that case, if the water content in the layer facing the side of the anode is too high, it reduces not only the strength of the membrane, but also increases the concentration of impurities contained in the resulting alkaline hydroxide.

On the other hand, as described in patent document 3, for example, also widely known method, for enhancing the strength of the membrane by sealing it porous substrate formed of woven material made of a fluorine-containing polymer such as polytetrafluoroethylene (PTFE).

Moreover, in Patent document 4 describes a method of increasing the strength of the membrane due to the convexity of the form of woven material made of PTFE or the like, toward the anode side. However, application of this method leads to the formation of the site, surrounded by protruding parts of a piece of woven material, which reduces if estvo aqueous solution of alkali chloride, applied to the anode surface of the membrane, which also depends on the conditions of the electrolysis device or cell, and increases the amount of impurities in the resulting alkaline hydroxide. For this reason, the quality alkaline hydroxide may not be stable.

Describes several ways of improving the shape of the surface of the membrane from the anode side to reduce the amount of oxygen in the chlorine generated from the anode during the electrolysis. In Patent document 5 describes a method of forming grooves by passing the membrane forms a crimping roller having protrusions, and in Patent document 6 describes a method of forming grooves by the embedding of the woven material in the surface of the membrane and Stripping. However, the ion-exchange membrane obtained by such methods should have a significantly smaller thickness of the layer of resin on the porous substrate, since the porous substrate made of PTFE or the like, pre-embedded in the membrane is pushed toward the back surface of a membrane having formed therein a groove, which reduces the strength of the membrane. During electrolysis ion-exchange membrane receives the load from all sides, therefore, the ion-exchange membrane obtained by such methods have significantly lower impedance is giving the load in the direction other than the directions of the porous substrate made of PTFE or the like, for example, load a 45-degree direction relative to the porous substrate, after which they are not able to provide stable performance over a long period of time. Moreover, the ability of the ion exchange membranes obtained by means of feeding an aqueous solution of alkali chloride in the space between the anode and the surface of the membrane does not improve sufficiently, and accordingly, does not reduces the amount of contaminants in the resulting alkaline hydroxide.

Patent document 1: JP-A-63-113029

Patent document 2: JP-A-63-8425

Patent document 3: JP-A-03-217427

Patent document 4: JP-A-04-308096

Patent document 5: JP-A-60-39184

Patent document 6: JP-A-06-279600

The INVENTION

The problem solved by this invention

In that case, if the alkaline hydroxide contains large amounts of impurities, especially alkali chloride solution, the hydroxide cannot be used to produce viscose rayon of cellulose, fibrous pulp, paper and chemical agent requiring the use of high-purity alkali hydroxide. Accordingly, the receipt of such cation exchange membrane for electrolysis, is able to reduce the concentration of contaminants get in the Christmas hydroxide, is highly desirable.

The present invention relates to an ion-exchange membrane for electrolysis, which can be used for electrolysis of an aqueous solution of alkali chloride, has a stable performance and at the same time maintains the electrochemical properties and mechanical strength over a long period of time, can improve the quality by reducing the amount of pollutants, especially in alkaline hydroxide, the resulting ion exchange, and therefore has a characteristic that is not used in the known process; and also relates to a method for producing such a membrane.

Solutions to assigned tasks

The authors of the present invention have conducted extensive studies aimed at solving the above problems, and as a result have found that the impurities in the resulting alkaline hydroxide are formed when the anion enters the membrane from the anode side, is connected with the cation and dissolved in catholyte in the form of impurities, and that this phenomenon is obvious in the case, when the flow of an aqueous solution of alkali chloride on the surface of the anode side of the membrane is insufficient, which led to the development of the present invention.

In more detail, the authors present asego invention was analyzed by ion-exchange membranes, used in electrolytic cells produced by different manufacturers and in different technological conditions, and as a result have found that when the anode being in close contact with the ion-exchange membrane, has a large area at high flux density for electrolysis or by electrolysis of an aqueous solution in the electrolytic cell without a gap, which ensures the contact of the cathode in the cell with the surface of the ion-exchange membrane from the cathode side of the ion exchange membrane, along the contour of the anode of the electrolytic cell formed small bubbles. Assessing performance, the authors of the present invention have found that the amount of impurities in the alkali hydroxide in this part increases.

The reason for the formation of small bubbles on the ion exchange membrane is as follows: an aqueous solution of alkali chloride is not supplied sufficiently to the part of the anode chamber, where the anode of the electrolytic cell is in close contact with the surface of the anode side of the ion exchange membrane, so the concentration of the aqueous solution of alkali chloride is reduced. Then to solve this problem, the authors of the present invention have studied various forms of the surface of the anode side of the ion exchange membrane and developed this invention.

Accordingly, aspects of the present is the first invention is described below.

1. Cation-exchange membrane for electrolysis, including

fluorine-containing polymer containing an ion-exchange group, and a porous substrate, wherein the membrane has a protruding part comprising a polymer containing an ion-exchange group on the surface of the anode side of the membrane;

20≤h≤150, where h is the average height (μm) from the surface of the anode side of the membrane to the tops of the protrusions;

50≤R≤1200, where P is the density (number/cm2) protrusions;

0,001≤S≤0.6, where S is the average area (cm2/cm2the lower surfaces of the protruding parts in the same plane as the surface of the anode side of the membrane; and

T≤0,05, where T is the average area (cm2/cm2) the upper parts of the protruding parts on the surface of the anode side of the membrane.

2. Cation-exchange membrane according to aspect 1, in which

0,5≤b/a≤0.9 and

0,25≤h/a≤0,80,

where a is the average length (μm) of the bottom sides of the protruding parts in the same plane as the surface of the anode side of the membrane; and b is the average value of the widths (μm) of the protruding parts in the middle of the height h/2 (μm) of the protruding parts.

3. Cation-exchange membrane according to any of aspects 1 and 2, in which the protruding parts are discontinuous with respect to each other.

4. Cation-exchange membrane with the according to any one of aspects 1-3, in which the protruding portion have the same shape or different shapes from two or more forms selected from the group including a form in the form of a circular cone shape in the form of a quadrangular pyramid shape in the form of a circular truncated cone shape in the form of a truncated quadrangular pyramid.

5. The method of obtaining an ion-exchange membrane for electrolysis, characterized by the implementation of close contact embossed remove the paper from the surface of the anode side of the membrane and the transfer of the embossed shape of the removable paper to the surface when applying the fluorine-containing polymer containing an ion-exchange group on the porous substrate, thereby forming a protruding portion containing polymer containing an ion-exchange group on the surface of the anode side.

6. Method according to aspect 5, in which close contact shooting paper with the surface of the anode side of the membrane by reducing the pressure to remove the paper.

7. Method according to aspect 5, in which the embossed form is the same form or different forms of two or more forms selected from the group including a form in the form of a circular cone shape in the form of a polygonal pyramid, a hemispherical shape, a dome shape, a shape in the form of a circular truncated cone shape in the form of a truncated polygonal pyramid.

8. rebar for electrolysis, containing cation exchange membrane according to one of aspects 1-4, the cathode and the anode, while the said device consists of a container for the electrolysis, the surface having the protruding portion of the cation exchange membrane is in contact with the anode or addressed to him.

Advantages of the invention

Fluorinated cation exchange membrane according to the present

the invention is able to reduce the content of impurities in the resulting alkaline hydroxide, while maintaining the electrochemical properties and mechanical strength for the electrolysis of an aqueous solution of alkali chloride, and to provide high-quality alkaline hydroxide over a long period of time.

PREFERRED embodiments of the INVENTIONS

The details of the present invention described below, particularly with reference to the preferred implementation.

The present invention relates to a cation exchange membrane for electrolysis, comprising the fluorine-containing polymer containing an ion-exchange group, and a porous substrate, wherein the membrane has a protruding part comprising a polymer containing an ion-exchange group on the surface of the anode side of the membrane; 20≤h≤150, where h denotes the average value of the heights of microns (μm) from the surface of the anode side of the membrane to manage the protrusions; 50 ≤R≤1200, where P is the density (number/cm2) protrusions; 0,001≤S≤0.6, where S denotes the average value of the area (cm2/cm2the lower surfaces of the protruding parts in the same plane as the surface of the anode side of the membrane; and T≤0,05, where T denotes the average value of the area (cm2/cm2) the upper parts of the protruding parts on the surface of the anode side of the membrane.

In this case, the surface of the anode side means the surface of the membrane facing the anode, when installing a cation exchange membrane for electrolysis according to the present invention into the cell. According to the present invention, the surface of the anode side has a protruding part comprising a polymer containing an ion-exchange group. In addition, according to the present invention, the surface of the membrane, including protruding parts, for convenience referred to as “the surface of the anode side even when the membrane is installed independently by itself, without embedding into the cell.

As described above, according to the present invention, the protruding portion comprising a polymer containing an ion-exchange group on the surface of the anode side of the membrane, preferably have a height which is at 20≤h≤150, more preferably 20≤h≤120, where h denotes the average amount is the height (μm) from the surface of the anode side of the membrane to the tops of the protrusions; the distribution density (number/cm2) protruding parts on the surface of the anode side of the membrane component 20≤R≤1500, more preferably 50≤R≤1200; the area of the bottom surface component of 0.001≤S≤0.6, where S denotes the average value of the parts area (cm2/cm2the lower surfaces in the same plane as the surface of the anode side of the membrane; and the area of the upper parts T≤0,05, where T means the average area (cm2/cm2upper parts. The authors did not expect that the protruding parts of this form on the surface of the anode side of the membrane will significantly increase the flow of aqueous solution of alkali chloride on the surface of the anode side of the membrane during electrolysis without reducing the mechanical strength or electrochemical properties of the membrane, and will significantly reduce the content of impurities in alkali hydroxide, the resulting electrolysis.

The protruding parts on the surface of the anode side of the membrane preferably have a value of b/a, component of 0.5≤b/a≤0,9, where a denotes the average value of the lengths (μm) of the bottom sides in the same plane as the surface of the anode side of the membrane, and b means the average width (μm) of the protruding parts in the middle of the height h/2 (μm) of the protruding parts. In that case, if the value of b/a is 0.5 or more, the ledge is the real part has a sufficient height within the preferred range of density distribution P protruding part, necessary in the present invention is able to sufficiently ensure the receipt of an aqueous solution of alkali chloride on the surface of the anode side of the membrane, does not reduce the strength of the protruding part and can easily keep its shape even when the membrane is pressed against the anode of the electrolyzer. In that case, if the value of b/a is 0.9 or more, the area of the protruding part being in contact with the anode of the electrolyzer, is not too large, the surface of the anode side of the membrane receives an adequate amount of an aqueous solution of alkali chloride. In addition, the strength of the protruding part is almost not reduced.

According to a preferred variant, the protruding parts are 0,25≤h/a≤0,80 from the standpoint of the ratio of the average height h (μm) of the protruding parts on the surface of the anode side of the membrane and the average length (μm) of the lower side of the protruding part in the same plane as the surface of the anode side of the membrane. In that case, if the value of h/a is 0.25 or more, the protrusions have a sufficient height, the aqueous solution of alkali chloride is supplied in a sufficient degree, the area of the protruding parts on the surface of the anode side of the membrane in contact with the anode of the electrolyzer, is not too large, the formation of small bubbles on member who may not be ingibirovalo and performance electrolysis can also be ingibirovalo. On the other hand, if the value of h/a is 0.8 or less, the strength of the protruding part is not reduced, which stabilizes the performance of the electrolysis.

The protruding portion comprising a polymer containing an ion-exchange group, preferably has breaks on the surface of the anode side of the membrane according to the present invention. The protruding portion having a specific shape, able to guarantee a sufficient supply of aqueous solution of alkali chloride solution during electrolysis. In this description, the expression “has breaks” means that the protrusions do not form a closed space on the surface of the anode side connecting with one another and forming a continuous wall within a narrow range of the membrane surface. The protruding portion on the surface of the anode side of the membrane preferably has the shape of a circular cone, a polygonal pyramid such as a triangular pyramid and square pyramid, hemisphere dome, a circular truncated cone or a truncated polygonal pyramid, more preferably, it has a circular conical shape, a circular truncated conical shape, a quadrangular pyramid shape, a truncated quadrangular pyramid shape or the like, because the shape plays a major role in the contact protruding castii anode of the electrolyzer, and in the balance sheet strength of the protruding part. The protruding parts of the surface of the anode side of the membrane can be of the same form or different forms of two or more forms selected from the above-mentioned forms.

In this case, the average length (μm) of the bottom sides in the same plane as the surface of the anode side of the membrane, define, cutting a cross-section of the membrane, passing through the top of the protruding part, in the form of a thin film and examining it under an optical microscope with 40-fold magnification. Specifically, in the case where the protruding portion has a shape of a circular cone, a circular truncated cone, a hemisphere or dome, the lower side of the protruding part was considered as a circle and its diameter. On the other hand, when the protruding portion has a shape of a quadrangular pyramid or a truncated quadrangular pyramid, the shape of the lower side was considered as a square and determined the length of its side. Determined the length of the side of the protruding part. An average value was calculated after measuring 10 parties in each case.

Then determined the average height h (μm) of the protruding parts and the half-height h/2 (μm) serving pieces, cutting off the thin film of the cross-section of the membrane, passing through the top of the protruding part, and examining it under an optical microscope with a 40-cranialsacral. An average value was determined after measuring 10 slices of the cross-section. Width b (μm) serving on the half-height h/2 extension was determined by measuring the diameter in the case where the protruding portion has a shape of a circular cone or a circular truncated cone, and measuring the length of a side in the case where the protruding portion has a shape of a quadrangular pyramid or a truncated quadrangular pyramid. An average value was calculated in a similar way after measuring 10 slices.

Moreover, the determined average value of the square S (cm2/cm2the lower surfaces of the protruding parts in the same plane as the surface of the anode side of the membrane, using the value of a and approximating the area of the lower surface to the area of a circle or polygon shape. The average T area (cm2/cm2) the upper part of the protruding part of the approximately determined, cutting a cross-section of the membrane in the form of a thin film; studying the protruding portion under an optical microscope with a 100-fold increase; calculating an average value of the width of the part 5 microns below the top of the protruding portion toward the bottom surface and taking the square cut shape for the area of a circle in the case where the protruding portion has a shape of a circular cone or a truncated circular cone, and taking the square is cut form for the square of polygonal shape in the case when the protruding portion has a shape of a pyramid or a truncated pyramid. In addition, the values of S and T, respectively, was defined as the percentage ratio of the areas of the lower face and the upper parts of the total surface area of the anode side of the membrane. The distribution density P (number/cm2) protruding parts was determined after measuring the surface of the anode side of the membrane under an optical microscope with 40-fold magnification.

The porous substrate used in the present invention, is used to give the membrane strength and dimensional stability, it requires that a large portion of the porous substrate was located in the membrane. It is necessary that such a porous substrate kept the heat resistance and chemical resistance over a long period of time and, preferably, was formed from fibers made from a fluorinated polymer. Examples of fluorinated polymer include polytetrafluoroethylene (PTFE), copolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), copolymer of tetrafluoroethylene-ethylene (ETFE), a copolymer of tetrafluoroethylene-hexaferrite, copolymer of triptoreline-ethylene polymer vinylidenefluoride (PVDF). However, particularly preferred is the use of fibers made from polyterephthalate the s.

The porous substrate used in the present invention, formed from fibers having a diameter of preferably from 20 to 300 denier, more preferably from 50 to 250 denier; and a weave density of the weave, component preferably 5-50 lines/inch. Used porous substrate has the form of woven fabric, non-woven cloth or knitted fabric, however, preferably, it has the form of woven fabric. Woven fabric has a thickness of preferably from 30 to 250 μm, more preferably from 30 to 150 microns.

In the woven fabric or knitted fabric for porous substrates use monofilament, multifilament fiber or yarn, split yarn or the like, it may be woven using different types of weaving, such as a flat weave, Leno weave, knitted fabric, cord weave and lightweight striped fabric.

Woven or knitted fiber fiber is the level of disclosure, comprising preferably 30% or more, more preferably 50% or more and 90% or less. The level of disclosure is preferably 30% or more from the viewpoint of electrochemical properties when used as ion-exchange membranes, and preferably 90% or less from the viewpoint of the mechanical strength of the membrane.

Particularly preferred form the Redi various forms of porous substrates is for example, the shape of the tape yarn obtained by slitting a high-strength porous sheet made of PTFE, in the form of a tape, or high-oriented monofilament size from 50 to 300 denier, made of PTFE having a planar structure of the weave density of the weave, part of from 10 to 50 lines/inch and having a thickness in the range from 50 to 100 μm and the level of disclosure in the amount of 50% or more. In addition, the woven fabric may include a carrier fiber, commonly called protective material of the core, to prevent deviation of the texture of the porous substrate in the process of obtaining membrane. Support fiber dissolves in the process of receiving membrane or in the electrolytic environment. The material used for the carrier fibers include viscose fiber, viscose rayon, cellulose, polyethylene terephthalate (PET), cellulose and polyamide. The amount of the mixed suspension of fiber in this case is preferably from 10 to 80 wt.%, more preferably from 30 to 70 wt.%, in relation to the entire woven fabric or just knitted fabric.

Fluorine-containing polymer used in the present invention, is a polymer formed from the main chain fluorinated hydrocarbon having a functional group in the terminal of the side chain, colorature to be converted into an ion-exchange group by hydrolysis and the like, and can also be formed from the melt.

What follows is a description of an example of a General method of obtaining such a fluorine-containing polymer.

Fluorine-containing polymer can be obtained by copolymerization of at least one monomer selected from the following first group, with at least one monomer selected from the following second group and/or third group.

The monomer of the first group represents the connection of winifrida, for example, at least one compound selected from winifrida, hexaferrite, vinylidenefluoride, triptorelin, chlorotrifluoroethylene, PERFLUORO(alkylvinyl ether) and tetrafluoroethylene, and when using a polymer, in particular, as a membrane for alkaline electrolysis, it is preferably selected from tetrafluoroethylene, PERFLUORO(alkylvinyl ether) and hexaferrite representing performancemore, not containing hydrogen.

The monomer of the second group is a vinyl compound having a functional group which can be converted into an ion-exchange group type of carboxylic acid. The most commonly used monomer has the formula CF2=CF(OCF2CYF)s-O(CZF)t-COOR. In this case, s is an integer from 0 to 2, t is an integer from 1 to 12, Y and Z represents F or CF3and R p is ecstasy a lower altergroup.

The preferred monomer is a compound expressed by the formula CF2=CF(CF2CYF)n-(CF2)m-COOR. In this case, n is an integer from 0 to 2, m is an integer from 1 to 4, Y represents F or CF3, R represents a CH3C2H5and C3H7.

When using a polymer, in particular, as a membrane for alkaline electrolysis, the monomer preferably is performanceline, only R (lower accelgroup) does not necessarily have to be the type of perftoran, because it disappears when the hydrolysis of the functional groups in ion exchange group. This is the preferred monomer includes, for example, CF2=CFCF2-CF(CF3)-O-CF2COOCH3, CF2=CFCF2CF(CF2)O(CF2)2COOCH3, CF2=CF[CF2-CF(CF3)]2O(CF2)2COOCH3, CF2=CFCF2CF(CF3)O(CF3)3COOCH3, CF2=CF(CF2)2COOCH3and CF2=CF(CF2)3COOCH3.

The monomer of the third group is a vinyl compound having a functional group which can be converted into an ion-exchange group type sulfone. The preferred compound expressed by the General formula CF2=CFO-X-CF2-SO2-F, where s submitted is a group selected from various kinds of perfluorinated carbon groups. Specific examples of such compounds include CF2=CFOCF2CF2SO2F, CF2=CFOCF2CF(CF3)OCF2CF2SO2F, CF2=CFOCF2CF(CF3)OCF2CF2CF2SO2F, CF2=CF(CF2)2SO2F, CF2=CFO[CF2CF(CF3)O]CF2CF2SO2F and CF2=CFOCF2CF(CF2OCF3)OCF2CF2SO2F, and particularly preferred examples of the above examples are CF2=CFOCF2CF(CF3)OCF2CF2CF2SO2F and CF2=CFOCF2CF(CF3)OCF2CF2SO2F.

The copolymer of these monomers can be obtained by the polymerization method, developed for one of fluorinated ethylene and its copolymer, in particular, the General method of polymerization used for tetrafluoroethylene. For example, there is a waterless method, comprising: using an inert fluid, such as a perfluorinated hydrocarbon and chlorpheniramine carbon as a solvent; use of a radical polymerization initiator, such as peroxide perfluorinated carbon and uzasadnienie; and providing the copolymerization at a temperature of from 0 to 200°C and a pressure of from 0.1 to 20 MPa.

The type and ratio of monomers used for the ACPs is imerissia, choose define from the above three groups according to the type and quantity of the desired functional groups necessary for fluorinated polymer.

For example, if you want a polymer containing a functional group of carboxylic ester, for copolymerization may be selected, at least one monomer, respectively, of the monomers of the first group and second group. On the other hand, when the polymer containing functional group of sulfonyl fluoride, for copolymerization may be selected, at least one monomer, respectively, of the monomers of the first group and third group.

Moreover, when the polymer containing both functional groups, carboxylic ester and sulfonyl fluoride, for copolymerization may be selected, at least one monomer, respectively, of the monomers of the first group, second group and third group.

In this case, the target fluorinated polymer may be received by a polymerization of a copolymer of the monomers of the first group and second group, and a copolymer of the monomers of the first group and the third group, followed by mixing copolymers. As for the mixing ratios of each monomer, if necessary, increase the number of desired functional groups on a single monomer may be increased soo is wearing monomers, selected from the second group or the third group.

After transformation of all functional groups in the exchange group, used ion-exchange membrane having an ion exchange capacity of preferably from 0.5 to 2.0 mg per weight/g dry resin, more preferably from 0.6 to 1.5 mg per weight/g dry resin in General.

The method of obtaining an ion-exchange membrane according to the present invention differs in that the protruding portion containing polymer containing an ion-exchange group is formed on the surface of the anode side, through close contact embossed remove the paper from the surface of the anode side, and carry the embossed shape of the removable paper to the surface when applying the fluorine-containing polymer containing an ion-exchange group on the porous substrate.

When the desired shape is pre-applied by embossing to remove the paper that is used when connecting film with a porous substrate, for receiving the protruding part on the anode side of the membrane surface, which is the aim of the present invention. The method of forming embossed form on removable paper includes, for example, the following stages: implementation of close contact shooting paper with a heated metal roller, on which the pre-form the desired protruding shape; and thrust to remove the paper is heated metal roller by means of pressure roller, made of resin, at a temperature of formation, component preferably from 2 to 120°C, more preferably from 25 to 80°C. under a linear pressure, the components preferably 500 n/cm or more, more preferably from 600 to 2000 n/cm, and with the speed forming component is preferably 50 m/min or less, more preferably 40 m/min or less. In addition, the depth of the extruding deepening can be adjusted by changing the linear pressure of pressure roller made of resin and designed for cuddling remove the paper by heated metal roller. The bulk is used remove the paper can be selected from a relatively wide range, however, from the point of view of technological resistance and heat resistance, it is preferable to range from 50 to 400 g/m2.

In addition, when transferring the extruded form on the membrane to maintain the mechanical strength of the membrane preferably the method includes the implementation of close contact shooting paper with the surface of the anode side of the membrane by reducing the pressure to remove the paper.

Moreover, in order to secure the transfer of previously extruded shapes, formed on the removed paper, on the surface of the anode side of the membrane is preferable regulirovanie the surface temperature of the membrane level, preferably amounting to 180°C. or higher and 300°C or below.

In addition, when the embossing remove the paper preferably using removable paper having air permeability, component of 0.03 MPa or less, preferably 0.025 MPa or less, and embossing remove the paper under reduced pressure to further improve prikleevaetsja remove the paper to the membrane and the guaranteed transfer of previously extruded shapes, formed on the removed paper.

Breathability removable paper is measured using a measuring device of the type pneumatic micrometer according to the standard of JAPAN TAPPI No. 5 - 1:2000.

Remove the paper may be of any embossed on her form, since the metal roller transfers the formed thereon tonilou form on the surface of the removable paper.

To achieve the objective of the present invention can be selected from various shapes, including a circular cone, a polygonal pyramid such as a triangular pyramid and square pyramid, a hemisphere, a dome, a circular truncated cone and a truncated pyramid, can also be selected mixed form of two or more of the above forms.

In addition, as described above, the average height of the embossed shape is preferably from 20 to 150 μm, more preferably from 20 to 150 MK is, since contact with the ion-exchange membrane on the surface of the anode side of the membrane is transferred approximately the same shape as embossed form. Moreover, the distribution density of the embossing is preferably from 20 to 1200 number/cm2more preferably from 50 to 1200 number/cm2. The average area of the bottom surfaces of the embossed shape is preferably from 0.001 to 0.6 cm2/cm2. The area of the upper part of the embossed shape differs depending on the embossed shape, but in any event preferably is 0.05 cm2/cm2or less.

Embossed shape preferably has such a relationship between a and b to satisfy the expression of 0.5≤b/a≤0,9, where a denotes the average value of the lengths of the bottom sides of the lower surfaces of the embossed shape, and b means the average value of the width at half height of the embossed shape; and, preferably, has the following relationship between a and h to satisfy the expression of 0.25≤h/a≤0.8 a, where a denotes the average value of the lengths of the bottom sides of the lower surfaces of the embossed shape, and h denotes the average value of the heights of the embossed shape.

When receiving the above-described membrane using removable paper membrane acquires a protruding part comprising a polymer containing an ion-exchange group, sformirovann the Yu on the surface of the anode side, the protrusions reduce prikleivalos membrane to the anode during electrolysis, the solution of alkali chloride solution on the anode side is sufficiently supplied to the surface of the anode side of the membrane. Thus, the purpose of the present invention can be achieved.

Embossed recess formed on the removed paper, preferably is intermittent. In that case, if the embossed recesses form a closed shape, such as a lattice, when transferring embossed shape on the surface of the anode side of the membrane forming a part surrounded by a projecting part. This is surrounded by a part hinders an adequate supply of solution of alkali chloride solution to the anode side during electrolysis.

Deepening, embossed on removable paper can be correct or random location, provided that such arrangement does not exceed the level density and the depth of the embossed recesses according to the present invention.

A particularly preferred method involves forming a film by joint extrusion of fluorine-containing polymer (first layer)containing the functional group of carboxylic ester and located on the cathode side, and a fluorine-containing polymer (the second layer)containing a functional group of sulfonyl fluoride. In addition you received the e film fluorine-containing polymer (a third layer)containing a functional group sulphonylchloride, separately formed into a film in advance. Obtained such films together, performing the following steps: placing the film of the third layer, the porous substrate and the composite film of the second layer with the first layer in the order listed on a flat plate or drum, provided with a heat source and a source of vacuum and having a lot of pores on its surface, using heat-resistant removable paper having gas permeability; and integrate them at a temperature at which melts each polymer, with simultaneous removal of air between the layers to reduce pressure. When this joint extrusion of the first layer and the second layer promotes the adhesion strength between the contact surfaces and the integration of layers under reduced pressure provides greater thickness of the third layer on the porous substrate in comparison with the method involving the use of high pressure. Moreover, a sufficient mechanical strength of the membrane can be saved, because the porous substrate is fixed on the inner side of the membrane.

In the above description with the aim of improving the electrical performance of the ion-exchange membrane, the fourth layer is provided is both functional groups, such as ether carboxylate and sulfonyl fluoride, may be placed between the first layer and the second layer, either the second layer may be replaced by a layer containing both a functional group such as carboxylic ester and sulfonyl fluoride. In this case, can be used a process comprising separate receipt polymer containing functional group of sulfonyl fluoride, and polymers containing functional group carboxylic ester, and then mixing the polymer, or may be used a process comprising the copolymerization of a monomer containing a functional group of a carboxylic ester and a monomer containing a functional group of sulfonyl fluoride. With the introduction of the fourth layer as the membrane structure can be formed jointly extruded film of the first layer and the fourth layer are separately formed in the form of films of the third layer and the second layer and stacked as described above, either simultaneously formed film by joint extrusion of three layers: the first layer, the fourth layer and the second layer.

The first layer has a thickness of component preferably from 5 to 50 μm, more preferably from 5 to 30 μm. The second layer has a thickness of component preferably from 30 to 120 μm, more preferably from 40 to 100 μm, because it is the Wallpaper layer, defines the strength of the membrane. The third layer has a thickness of component preferably from 15 to 50 μm. Moreover, with the introduction of the above-described fourth layer between the first layer and the second layer of the total thickness of the ion-exchange membrane to hydrolysis should preferably be 200 μm or less, more preferably from 50 to 180 μm. Particularly preferred is a thickness of the membrane, component of 50 μm or more from the viewpoint of mechanical strength, and 180 μm or less from the point of view of the electrolytic resistance.

As stated above, the cation exchange membrane for electrolysis must provide a low voltage. As one of the ways to reduce stress, uses a method of reducing the thickness of the layer made of fluorinated resin containing a carboxylic acid group, and a layer made of fluorinated resin containing a sulfonic acid group. In this case, with regard to the strength of the membrane, the problem arises, namely that the strength of the membrane is reduced in proportion to the thickness of the membrane. To prevent strength reduction membrane is used way to seal the porous substrate made of PTFE or the like, in the membrane, however, the ion-exchange membrane consisting of a porous substrate, makes the resin porous layer around on the spoon thinnest part, that has a strong influence on the strength of the membrane.

Accordingly, in order to avoid reducing the strength of the ion-exchange membrane, it is necessary to use technological way not reducing the thickness of the resin layer around the porous substrate.

The method of moving embossed shapes, pre-formed to remove the paper on the surface of the membrane according to the present description can deliver intermittent protrusions consisting of fluorinated resin on the surface of the anode side of the ion exchange membrane without thinning the resin layer around the porous substrate, and can also improve the shape of the surface of the anode side of the membrane, without reducing the strength of the membrane. Furthermore, the method of receiving according to the present invention does not require direct contact of fluorine-containing polymer with a roller and, therefore, capable of preventing corrosion of metal roller even when the formation of the protrusions, for example, by means of a metal clip. Moreover, the method of receiving according to the present invention provides for the formation of small and discontinuous protrusions on the surface of the anode side of the membrane and, consequently, reduces the contact area between the anode in the electrolytic tank and the surface of the membrane, provides the residual receipt of a solution of alkali chloride and accordingly, capable of greatly reduce the amount of contaminants in the resulting alkaline hydroxide.

If necessary, the membrane according to the present invention may have a layer of inorganic coating to prevent trapping of gases on the surfaces of the cathode side and anode side. The coating layer may be formed on the membrane, for example, by spraying a liquid containing fine particles of inorganic oxide dispersed in a polymeric binding solution.

Fluorinated cation exchange membrane according to the present invention can be used for different types of electrolysis, but below is a representative example illustrating the use of such membranes for the electrolysis of an aqueous solution of alkali chloride. For electrolysis can be used known conditions. For example, the conditions for electrolysis include temperature electrolysis, comprising from 50 to 120°C., and the flux density, comprising from 5 to 100 A/DM2when submitting from 2.5 to 5.5 normal (N) aqueous solution of alkali chloride in the anode chamber and water or a dilute aqueous solution of alkali hydroxide in the cathode chamber.

Electrolysis, which uses a fluorine-containing cation exchange membrane for electrolysis according to the present image is ateneu, can be a odnoelektrodnogo electrolyzer or two-electrode cell, provided that the tub has the structure described above, including the cathode and the anode. The cell is preferably made, for example, of titanium as a material having resistance against alkali chloride and chlorine in the anode chamber, and Nickel as a material having resistance against alkali hydroxide and hydrogen in the cathode chamber. With regard to the location of the electrodes, fluorine-containing cation exchange membrane for electrolysis according to the present invention and the anode may be located at a suitable distance, however, when using the membrane according to the present invention, this goal can be achieved without any difficulty, even if the anode and the ion exchange membrane are arranged in such a way as to be in contact with each other. In addition, the cathode is usually placed adjacent to the ion-exchange membrane at a suitable distance, however, the advantage provided by the present invention is not lost even in the electrolysis of the contact type, which does not have such space (the electrolyzer without a gap).

Further, the present invention is described with reference to examples and comparative examples.

Examples

The present invention is described below with the reference to examples and comparative examples, however, it is not limited to the given examples.

In the examples and comparative examples, the electrolysis is carried out in an electrolysis cell with automatic circulation size 1 DM2with the cathode of the metal grid and the anode of a porous plate (having a pore size of 4 Φ located in 6 steps, the value of the open space which is 40%), at the temperature of 90°C, the flux density of 60 A/DM2within seven days, when applying to an anode side of an aqueous solution of sodium chloride, the concentration of which is to regulate the level of 205 g/l, maintaining the concentration of caustic soda in the cathode side at the level of 32 wt.% and adjusting the differential pressure between the fluid pressure at the cathode side of the cell and the fluid pressure on the anode side so that the fluid pressure at the cathode side was higher by 8.8 kPa.

Example 1

Woven fabric with a thickness of 100 μm receive in the form of a porous substrate, performing the following steps: receiving thread by twisting the tape yarn of 100 denier, polytetrafluoroethylene (PTFE), with frequency of 900/m; receiving the carrier fiber (security thread) by twisting 6 of filaments made of polyethylene terephthalate (PET) size 30 denier with a frequency of 200 times/m as the basis; obtaining a duck by crucian the I 8 of filaments from the filament PET size 30 denier with a frequency of 10 times/m and the flat weave of the obtained filaments with alternative intertwining threads of PTFE in the amount of 24 threads per inch and protective threads in the amount of 64 threads per inch that provides 4 times higher density than the density provided by the threads of PTFE. The thickness of the obtained woven fabric regulate at the level of 70 μm by crimping the heated metal roller. The value of open space only thread PTFE is 75%.

Then get the polymer (A)constituting the copolymer of CF2=CF2and CF2=CFOCF2CF(CF3)OCF2CF2COOCH3and having ion exchange capacity, component of 0.85 mg equivalent/g of dry resin; receive the polymer (B)constituting the copolymer of CF2=CF2and CF2=CFOCF2CF(CF3)OCF2CF2SO2F and having an ion exchange capacity component of 0.95 mg equivalent/g of dry resin; and receive the polymer (C)having the same structure as the polymer (B), and ion-exchange capacity, component of 1.05 mg equivalent/g dry resin. Film (x) with dual layer receive joint extrusion of the above-mentioned polymers through a flat mouthpiece. Of the polymer (a) to form a film thickness of 25 μm, and the polymer (B) is a thickness of 75 μm. In addition, the film (have) a thickness of 25 μm produced from polymer (S) using a flat tip to obtain a single layer.

Then get a metal roller having protrusions (protrusions) on the surface having the shape of a circular truncated cone is, the average height of 150 μm, density distribution, which is about 500 quantity/cm2the area of the bottom face, a component of) 0.157 cm2/cm2the length of the bottom sides equal to 200 μm, and a width of 125 μm at the half height of the protruding part, and heated to 40°C; remove the paper form the embossed shape with the main mass component of 127 g/m2by crimping remove the paper heated metal roller and the pressure roller from the resin at a linear pressure of 1000 n/cm for the pressure roller from the resin, at a speed stamping equal to 10 m/min

The permeability used in this case, remove the paper before stamping is 0,005 MPa when the dimension measuring instrument of the type pneumatic micrometer according to the technical standard of the JAPAN TAPPI NO.5 - 1:2000.

Composite membrane receive, through the following stages: laying in a stack of removable paper, film, porous substrate and film (x) obtained from different materials in the order listed on the drum, provided inside the heat source and the source of vacuum and having a lot of pores on its surface; crimping stacked films at their simultaneous heating and reduced pressure; and then removing the removable paper. The temperature of the molding with the hat 225°C, as the vacuum pressure is equal to 0.022 MPa.

We studied the surface of the obtained membrane and as a result, it was found that the film (s) on the anode side has a protruding part formed on her truncated cones, with the average height h of about 45 μm; distributed with density P, component 500 number/cm2; with average S square face about 0,04 cm2/cm2; with the average squares T of the upper parts about 0,012 cm2/cm2; with the average length and the lower sides of about 100 microns and having an average width b of about 75 μm at the middle height of the protruding part, and is made of a polymer containing an ion-exchange group. In this case the value b/a is 0.75, and the value of h/a is 0.45.

After that, the obtained composite membrane hydrolyzing at 90°C for one hour, and then washed and dried. In addition, receive a suspension, adding and dispersive 20 wt.% particles of zirconium oxide with a primary particle diameter constituting 0.02 mm, in ethanol containing 5 wt.% polymer acid type polymer (C), then, on both surfaces of the above described composite membranes form the emitting gas film mass 5 mg/cm2by spraying a suspension of the appropriate method.

Determine the tensile strength, relative lengthened the e tensile and performance electrolysis of fluoride-containing cation-exchange membrane, obtained by the method described above. Measurement of tensile strength and relative elongation at elongation according to JIS K6732 includes the following stages: obtaining a sample taken from the membrane in the direction of 45° with respect to the porous substrate, embedded in the membrane and having a width of 1 cm; and stretching the sample at a distance of 50 mm between the clamps and the speed of stretching of 100 mm/min Electrolysis is carried out in the above electrolytic cell in which the film (I) place the front surface to the anode when the flux density, component 60 A/DM2and a temperature of 90°C for seven days. Measure the voltage of the electrolysis, the utilization of current and the amount of sodium chloride in the resulting caustic soda, and the stability of the electrolysis determine, based on the respective measurement results obtained on the second day and the seventh day after the start of electrolysis. The amount of sodium chloride in the resulting caustic soda (NaCl/50%-NaOH) set as follows: determine the amount resulting from the implementation stages of the interaction between ions of sodium chloride in caustic soda with mercury thiocyanate to thiocyanate ions; interact ions, thiocyanate ions, iron (III) to obtain thiocyanate iron (III) and measure the intensity of this color, called Tiziana the om iron (III); and recalculate the value obtained in the calculation of the option in which the concentration of the solution of caustic soda is 50 wt.%.

The results are presented in the table together with the results of other examples and comparative examples. The membrane has the values of tensile strength and relative elongation tensile quite acceptable for electrolysis. It was also found little performance deterioration of the membrane on the second day after the start of electrolysis and on the seventh day, oversleeve amount of sodium chloride contained in caustic soda, no noticeable improvement even on the seventh day after the start of electrolysis and, therefore, sustainable performance electrolysis.

Example 2

Remove the paper is subjected to embossing by means of pressure roller from the resin at a linear pressure of 800 n/a see Composite membrane receive the same manner as in Example 1, so that the protruding parts consisting of a polymer containing an ion-exchange group, formed on the surface of the anode side, had an average height h of about 33 microns; were distributed with density P, component 500 number/cm2; had an average value S of the square bottom face about of 0.025 cm2/cm2; had an average value of the T square in rhna parts about 0,012 cm 2/cm2; had an average length and lower sides of about 80 microns and had an average width b of about 67 μm at the middle height of the protruding part. In this case the value b/a is approximately 0.84, and the value of h/a is about 0,41. The obtained composite membrane is subjected to electrolysis under the same conditions as in Example 1. The results are presented in the Table in this way. In Example 2 were obtained adequate results similar to the results from Example 1.

Example 3

Metal roller with projections

Get a metal roller having protrusions (protrusions) on the surface having the shape of a quadrangular pyramid, the average height of 150 μm, density distribution, which is about 250 number/cm2the area of the bottom face constituting 0.4 cm2/cm2the length of the bottom sides equal to 400 μm, and the width is 225 μm at the half height of the protruding part, and heated to 40°C; remove the paper form the embossed shape with the main mass component of 127 g/m2by crimping remove the paper heated metal roller and the pressure roller from the resin at a linear pressure of 1100 n/cm for the pressure roller from the resin, at a speed stamping equal to 10 m/min Composite membrane obtained by the shooting paper in the same manner as in Example 1.

B is lo received another confirmation of the fact, that composite membrane made of a polymer containing an ion-exchange group has a protruding part formed on the surface of the anode side, which have an average height h of about 66 μm; distributed with density P, component 250 number/cm2; have an average size S of the square bottom face of about 0.1 cm2/cm2; has an average value T of the square upper parts about 0,009 cm2/cm2; is the average length and the lower sides of about 200 μm and have an average width b of about 125 μm at the middle height of the protruding part. In this case the value b/a is approximately 0.63, and the value of h/a is about 0.33. The obtained composite membrane is subjected to electrolysis under the same conditions as in Example 1. The results are presented in Table 1 in a similar way. In Example 2 were obtained adequate results similar to the results from Example 1.

Example 4

Remove the paper is subjected to embossing at a linear pressure of 1400 n/cm for the pressure roller from the resin. Composite membrane receive the same manner as in example 3, so that the protruding parts consisting only of a polymer containing an ion-exchange group, formed on the surface of the anode side, had an average height h of about 95 microns; were distributed with density P, component 250 is number/cm 2; had an average value S of the square bottom surface, occupying about 0,18 cm2/cm2; had an average value T of the square of the upper parts, occupying about 0,009 cm2/cm2; had an average length and lower sides of about 270 microns and had an average width b of about 67 μm at the middle height of the protruding part. In this case the value b/a is about to 0.50, and the value of h/a is about 0.35. The obtained composite membrane is subjected to electrolysis under the same conditions as in Example 1. The results are presented in the Table in this way. In Example 4 were obtained adequate results similar to the results from Example 1.

Comparative Example 1

The composite membrane obtained using removable paper that has not been subjected to embossing, in the same manner as in Example 1, and evaluate its properties. After studying the surface of the anode side was marked by the absence of such a prominent part, as in the previous examples. The results presented in the Table. In Comparative Example 1, the mechanical strength is adequate, which was confirmed in a tensile test, however, utilization of current when assessing the performance of electrolysis is much lower, the content of sodium chloride in caustic soda is high even for a second on the HB after the start of electrolysis and very high on the seventh day.

Comparative Example 2

Remove the paper is subjected to embossing at a linear pressure of 400 n/cm for the pressure roller from the resin. Composite membrane receive the same manner as in Example 3, so that the protruding parts consisting of a polymer containing an ion-exchange group, formed on the surface of the anode side, had an average height h of about 16 microns; were distributed with density P, component 250 number/cm2; had an average value S of the square bottom face, occupying about 0,019 cm2/cm2; had an average value T of the square of the upper parts, occupying about 0,009 cm2/cm2; had an average length and lower sides about 87 μm and had an average width b of about 46 μm at the middle height of the protruding part. In this case the value b/a is about to 0.53, and the value of h/a is about to 0.18. The obtained composite membrane is subjected to electrolysis under the same conditions as in Example 1. The results are presented in the Table in the same way. Like Comparative Example 1, the mechanical strength in the Comparative Example 2 is adequate, however, utilization of current when assessing the performance of electrolysis is much lower, the content of sodium chloride in caustic soda is high even on the second day after the beginning of the La electrolysis.

Comparative Example 3

Remove the paper is subjected to embossing at a linear pressure of 400 n/cm for the pressure roller from the resin. Composite membrane receive the same manner as in Example 1, so that the protruding parts consisting of a polymer containing an ion-exchange group, formed on the surface of the anode side, had an average height h of about 15 microns; were distributed with density P, component 500 number/cm2; had an average value S of the square bottom face, occupying about is 0.017 cm2/cm2; had an average value T of the square of the upper parts, occupying about 0,012 cm2/cm2; had an average length and lower sides of about 65 microns and had an average width b of about 35 μm at the middle height of the protruding part. In this case the value b/a is about 0.54, and the value of h/a is about to 0.23. The obtained composite membrane is subjected to electrolysis under the same conditions as in Example 1. The results are presented in the Table. Mechanical strength in Comparative Example 3 is also adequate, but the utilization of current when assessing the performance of electrolysis is much lower, the content of sodium chloride in caustic soda is high even on the second day after the start of electrolysis.

UnitExample 1Example 2
The polymer (A) or the layer made of the polymer (A)Ion-exchange capacitymg equivalent/
g dry resin
0,850,85
Thicknessmcm2525
The polymer (A) or the layer made of the polymer (In)Ion-exchange capacitymg equivalent/
g dry resin
0,950,95
Thicknessmcm7575
The polymer (S) or layer made of polymer (C)Ion-exchange capacitymg equivalent/
g dry resin
1,051,05
Thicknessmcm2525
The average height (h) of the protruding part on the front side of the anodemcm4533
The density distribution (R) protruding part on the front side of the anodenumber/cm2500500
Average area (S) lower sides of the protruding part on the front side of the anodecm2/1 cm20,040,025
Average area (T) of the upper part of the protruding part on the front side of the anodecm2/1 cm20,0120,012
The average length of the (a) bottom side protruding part on the front side of the anodemcm10080
Average width (b) at half the height of the protruding part on the front side of the anodemcm75 67
b/a-0,750,84
h/a-0,450,41
The shape of the protruding part on the front side of the anode-Circular truncated coneCircular truncated cone
Rupture teststrengthkg/cm1,531,54
extension%5553
Voltage electrolysisthe second dayv3,533,55
the seventh day3,54of 3.56
The utilization rate currentthe second day%96,3 96,7
the seventh day96,596,6
The content of sodium chloride in caustic soda (NaCl/50%-NaOH)the second dayrpm1520
the seventh day2545

Example 3Example 4Comparative Example 1Comparative Example 2Comparative Example 3
0,850,850,850,850,85
2525252525
0,950,950,950,950,95
75757 7575
1,051,051,051,051,05
2525252525
6695-1615
250250-250500
0,100,18-0,0190,017
0,0090,009-0,0090,012
200270-8765
125135-4635
0,63 0,50-0,530,54
0,330,35-0,180,23
Rectangular
pyramid
Rectangular
pyramid
-Rectangular
pyramid
Circular truncated cone
1,551,501,831,631,65
5550655858
3,493,55of 3.563,553,55
3,503,523,55to 3.58to 3.58
96,596,595,596,196,0
96,294,6for 95.3for 95.2
1812756558
3724250184120

INDUSTRIAL APPLICABILITY

Cation-exchange membrane for electrolysis according to the present invention are able to reduce the content of impurities in the resulting alkaline hydroxide, while maintaining good electrochemical properties and mechanical strength for the electrolysis of an aqueous solution of alkali chloride, provides the alkaline hydroxide of high quality, able to maintain stable performance electrolysis for a long period of time and contribute to a significant reduction of the cost of electrolysis and obtaining alkali hydroxide of high purity.

1. Cation-exchange membrane for electrolysis, comprising the fluorine-containing polymer containing an ion-exchange group, and a porous substrate, characterized in that on the surface of the anode side of the membrane has a protruding part comprising the fluorine-containing polymer containing ionoobmennogo, this
20≤h≤150, where h is the average value of heights from the surface of the anode side of the membrane to the top of the protruding parts, microns;
50≤R≤1200, where P is the density of the protrusions, the number/cm2;
0,001≤S≤0.6, where S is the ratio of the areas of the bottom surfaces of the protruding parts to the total area of the anode side of the membrane; and
T≤0,05, where T is the ratio of the areas of the upper parts of the protruding parts to the total area of the anode side of the membrane.

2. Cation-exchange membrane according to claim 1, in which
0,5≤b/a≤0.9 and
0,25≤h/a≤0,80,
where a is the average length of the bottom sides of the protruding parts in the same plane as the surface of the anode side of the membrane, μm; and b is the average width of the protruding parts in the middle of the height h/2 (μm) of the protruding parts, mm.

3. Cation-exchange membrane according to claim 1, in which the protruding parts are discontinuous with respect to each other.

4. Cation-exchange membrane according to claim 2, in which the protruding parts are discontinuous with respect to each other.

5. Cation-exchange membrane according to any one of claims 1 to 4, in which the protruding portion have the same shape or different shapes from two or more forms selected from the group including a form in the form of a circular cone shape in the form of a quadrangular pyramid shape in the form of a circular truncated cone shape in the form of a truncated quadrangular peers is water.

6. A method of obtaining a cation exchange membrane for electrolysis, characterized by the implementation of close contact embossed remove the paper from the surface of the anode side of the membrane and the transfer of the embossed shape of the removable paper to the surface when applying the fluorine-containing polymer containing an ion-exchange group on the porous substrate, thereby forming a protruding portion that includes a fluorine-containing polymer containing an ion-exchange group on the surface of the anode side.

7. The method according to claim 5, wherein remove the paper has a permeability, a component of 0.03 MPa or less, and lead her into close contact with the surface of the anode side of the membrane by reducing the pressure to remove the paper.

8. The method according to claim 5, in which the embossed form is the same form or different forms of two or more forms selected from the group including a form in the form of a circular cone shape in the form of a polygonal pyramid, a hemispherical shape, a dome shape, a shape in the form of a circular truncated cone shape in the form of a truncated polygonal pyramid.

9. Device for electrolysis containing cation exchange membrane according to any one of claims 1 to 4, the cathode and the anode, while the said device consists of a container for the electrolysis, the surface having the protruding portion of the cation exchange membrane is, in contact with the anode or addressed to him.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method of making an electrode for electrochemical processes involves electrodeposition of an electrocatalytic coating based on mixed oxides of base metals on a titanium surface. The said coating on the titanium surface is formed through electrodeposition from an aqueous solution of an electrolyte which contains salts of cobalt, manganese, nickel and boric acid under the effect of alternating asymmetrical current in which the current amplitude ratio of the anode and cathode half-cycles is 2:1, at voltage of 8-10 V, with the following ratio of components (g/l): cobalt sulphate (CoSO4·7H2O) - 100.0-110.0, manganese sulphate (MnSO4·5H2O) - 20.0-25.0, nickel sulphate (NiSO4·7H2O) - 15.0-20.0, boric acid (H3BO3) - 25.0-30.0, with subsequent thermal treatment in an oxidising atmosphere at 350-380°C for 30 minutes.

EFFECT: invention increases corrosion resistance and electrocatalytic activity of the electrode, increases bonding strength of the coating with the titanium substrate, reduces the cost of making the electrode and energy consumption of the process.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method of making an electrode for electrochemical processes involves electrodeposition of an electrocatalytic coating based on mixed oxides of base metals on a titanium surface. The said coating on the titanium surface is formed through electrodeposition from an aqueous solution of an electrolyte which contains salts of cobalt, manganese, nickel and boric acid under the effect of alternating asymmetrical current in which the current amplitude ratio of the anode and cathode half-cycles is 2:1, at voltage of 8-10 V, with the following ratio of components (g/l): cobalt sulphate (CoSO4·7H2O) - 100.0-110.0, manganese sulphate (MnSO4·5H2O) - 20.0-25.0, nickel sulphate (NiSO4·7H2O) - 15.0-20.0, boric acid (H3BO3) - 25.0-30.0, with subsequent thermal treatment in an oxidising atmosphere at 350-380°C for 30 minutes.

EFFECT: invention increases corrosion resistance and electrocatalytic activity of the electrode, increases bonding strength of the coating with the titanium substrate, reduces the cost of making the electrode and energy consumption of the process.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry, more specifically to a method of producing 2-aminoethanesulfonic acid by reacting 2-aminoethylsulphuric acid with excess sodium sulphate in an aqueous solution and boiling for 20 hours with subsequent separation of the desired product from mineral salts through electrodialysis at temperature 30-45°C and constant current density of 1.2-3.0 A/dm2.

EFFECT: reduced power consumption of the process and intensification of the technology with high current output of the product.

1 cl, 4 ex

FIELD: metallurgy.

SUBSTANCE: method of fabrication of electrode for electrolysis of water solutions of alkali metal chlorides consists in preliminary treatment of electrode titanium base surface, in application coating onto it, where coating consists of thermo-decomposed compounds of titanium, iridium and ruthenium; further the method consists in their succeeding thermal treatment in oxidising atmosphere and in producing electro-catalytic coating containing oxides of titanium, iridium and ruthenium; also surface of electro-catalytic coating is additionally treated with 20-25% water solution of hydrogen peroxide by means of sputtering it at amount of 80-140 g/m2 and successively heat treated at temperature of 450-480°C.

EFFECT: raised resistance of electrode, increased service life.

5 cl, 4 tbl

FIELD: metallurgy.

SUBSTANCE: at first surface of nickel containing material is degreased, further it is treated approximately for 10 minutes to make surface rough in approximately 1% solution of hydrochloric acid; also process is accelerated with addition of hydrogen peroxide. Surface of nickel containing material is washed, then this material is inserted into 3.5 molar solution of caustic alkali mixed with approximately 10% hydrogen peroxide and maintained there approximately for 10 minutes. In the following thermal process surface of nickel hydroxide thereby obtained is dehydrated and oxidised to nickel oxide. The invention also refers to electro-conducting surface layer thus obtained, also to electrodes produced out of it, to their application in the process of chlorine-alkaline electrolysis and in fuel elements and accumulators.

EFFECT: facilitating extremely high electro-conductivity of nickel oxide surface layers.

9 cl, 2 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: sodium silicate solution is treated outside an electrolysis cell with an anodic acid aqueous solution flowing from the anode chamber of the electrolysis cell at pH 3-4. The anodic acid solution is obtained through electrolysis of tap water in flowing mode.

EFFECT: invention increases purity of silica gel by avoiding contamination with sodium sulphate and reduces power consumption on production.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing fluorine and specifically to design of a medium temperature electrolysis cell for industrial production of fluorine from molten potassium trifluoride. The electrolysis cell has a housing, a cover, gas-distributing devices, a device for supplying hydrogen fluoride, a heat exchange system, an anode block and a cathode block with louvred walls, one of which is formed by two sets of louvred plates, which provide for gas-electrolyte emulsion containing cathode gas, a bottom-up zig-zag channel between the sets of walls. In each of the two sets of this wall, the plates lie one on top of the other, both sets lie at a distance from each other such that there is no gap between them in the vertical direction, the angle of deviation from the vertical of the plates of one set is equal on value but opposite to the sign of the angle of deviation from the vertical of plates in the other set. The plates deviate in directions opposite the anodes. Plates from one set are shifted on the vertical relative plates from the other set such that, the upper face of each plate of one set does not lie below the lower face of the nearest above-lying plate of the other set.

EFFECT: proposed electrolysis cell increases specific output of fluorine to 6,5 g/l/hour.

5 cl, 5 dwg

FIELD: chemistry.

SUBSTANCE: method of making an electrode for electrochemical processes involves electrodeposition of an electrocatalytic coating based on mixed oxides of base metals on a titanium surface. The said coating on the titanium surface is formed through electrodeposition from an aqueous solution of an electrolyte which contains salts of cobalt, manganese, nickel and boric acid under the effect of alternating asymmetrical current in which the current amplitude ratio of the anode and cathode half-cycles is 2:1, at voltage of 8-10 V, with the following ratio of components (g/l): cobalt sulphate (CoSO4·7H2O) - 100.0-110.0, manganese sulphate (MnSO4·5H2O) - 20.0-25.0, nickel sulphate (NiSO4·7H2O) - 15.0-20.0, boric acid (H3BO3) - 25.0-30.0, with subsequent thermal treatment in an oxidising atmosphere at 350-380°C for 30 minutes.

EFFECT: invention increases corrosion resistance and electrocatalytic activity of the electrode, increases bonding strength of the coating with the titanium substrate, reduces the cost of making the electrode and energy consumption of the process.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method of making an electrode for electrochemical processes involves electrodeposition of an electrocatalytic coating based on mixed oxides of base metals on a titanium surface. The said coating on the titanium surface is formed through electrodeposition from an aqueous solution of an electrolyte which contains salts of cobalt, manganese, nickel and boric acid under the effect of alternating asymmetrical current in which the current amplitude ratio of the anode and cathode half-cycles is 2:1, at voltage of 8-10 V, with the following ratio of components (g/l): cobalt sulphate (CoSO4·7H2O) - 100.0-110.0, manganese sulphate (MnSO4·5H2O) - 20.0-25.0, nickel sulphate (NiSO4·7H2O) - 15.0-20.0, boric acid (H3BO3) - 25.0-30.0, with subsequent thermal treatment in an oxidising atmosphere at 350-380°C for 30 minutes.

EFFECT: invention increases corrosion resistance and electrocatalytic activity of the electrode, increases bonding strength of the coating with the titanium substrate, reduces the cost of making the electrode and energy consumption of the process.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry, more specifically to a method of producing 2-aminoethanesulfonic acid by reacting 2-aminoethylsulphuric acid with excess sodium sulphate in an aqueous solution and boiling for 20 hours with subsequent separation of the desired product from mineral salts through electrodialysis at temperature 30-45°C and constant current density of 1.2-3.0 A/dm2.

EFFECT: reduced power consumption of the process and intensification of the technology with high current output of the product.

1 cl, 4 ex

FIELD: metallurgy.

SUBSTANCE: method of fabrication of electrode for electrolysis of water solutions of alkali metal chlorides consists in preliminary treatment of electrode titanium base surface, in application coating onto it, where coating consists of thermo-decomposed compounds of titanium, iridium and ruthenium; further the method consists in their succeeding thermal treatment in oxidising atmosphere and in producing electro-catalytic coating containing oxides of titanium, iridium and ruthenium; also surface of electro-catalytic coating is additionally treated with 20-25% water solution of hydrogen peroxide by means of sputtering it at amount of 80-140 g/m2 and successively heat treated at temperature of 450-480°C.

EFFECT: raised resistance of electrode, increased service life.

5 cl, 4 tbl

FIELD: metallurgy.

SUBSTANCE: at first surface of nickel containing material is degreased, further it is treated approximately for 10 minutes to make surface rough in approximately 1% solution of hydrochloric acid; also process is accelerated with addition of hydrogen peroxide. Surface of nickel containing material is washed, then this material is inserted into 3.5 molar solution of caustic alkali mixed with approximately 10% hydrogen peroxide and maintained there approximately for 10 minutes. In the following thermal process surface of nickel hydroxide thereby obtained is dehydrated and oxidised to nickel oxide. The invention also refers to electro-conducting surface layer thus obtained, also to electrodes produced out of it, to their application in the process of chlorine-alkaline electrolysis and in fuel elements and accumulators.

EFFECT: facilitating extremely high electro-conductivity of nickel oxide surface layers.

9 cl, 2 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: sodium silicate solution is treated outside an electrolysis cell with an anodic acid aqueous solution flowing from the anode chamber of the electrolysis cell at pH 3-4. The anodic acid solution is obtained through electrolysis of tap water in flowing mode.

EFFECT: invention increases purity of silica gel by avoiding contamination with sodium sulphate and reduces power consumption on production.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing fluorine and specifically to design of a medium temperature electrolysis cell for industrial production of fluorine from molten potassium trifluoride. The electrolysis cell has a housing, a cover, gas-distributing devices, a device for supplying hydrogen fluoride, a heat exchange system, an anode block and a cathode block with louvred walls, one of which is formed by two sets of louvred plates, which provide for gas-electrolyte emulsion containing cathode gas, a bottom-up zig-zag channel between the sets of walls. In each of the two sets of this wall, the plates lie one on top of the other, both sets lie at a distance from each other such that there is no gap between them in the vertical direction, the angle of deviation from the vertical of the plates of one set is equal on value but opposite to the sign of the angle of deviation from the vertical of plates in the other set. The plates deviate in directions opposite the anodes. Plates from one set are shifted on the vertical relative plates from the other set such that, the upper face of each plate of one set does not lie below the lower face of the nearest above-lying plate of the other set.

EFFECT: proposed electrolysis cell increases specific output of fluorine to 6,5 g/l/hour.

5 cl, 5 dwg

FIELD: processes and equipment for treatment of water with oxygen-containing gas, water bottling and treatment of bottles for adequate storage of water, may be used in industrial enterprises.

SUBSTANCE: method involves producing oxygen-saturated water by ejection-floatation mixing of water with oxygen-containing gas; bottling oxygen-saturated water and capping, with gas-and-vapor H2O2+O2 mixture synthesized by plasma chemotronical method being used in all above operations. Complex of equipment comprises ejection-floatation unit for oxygen saturation of water and installation for supplying and bottling of oxygen-saturated water.

EFFECT: improved quality of bottled oxygen-saturated potable water, increased storage time and reduced consumption of power and materials.

4 cl, 1 dwg, 4 tbl

Up!