JPS5842626A - Production of fluorine-containing ion exchange resin membrane - Google Patents

Abstract

PURPOSE:To produce the titled resin membrane excellent in surface hydrophilicity and mechanical properties and capable of lowering an electrolytic cell voltage, by forming a mixture of a fluorine-containing ion exchange resin and a specified amount of a finely divided inorganic substance into a membrane. CONSTITUTION:A fluorine-containing ion exchange resin membrane, ion exchange capacity 0.5-4.0meq/g dry resin, is prepared by uniformly mixing 100 pts.wt. ion exchangeable group-containing, fluorine-containing ion exchange resin consisting of 99-60mol% polymer unit of formulaI, wherein X is F, Cl or CF3, X' is X or CF3(CF2)m and m is 1-5, and 1-40mol% polymer unit of formula II, wherein Y is a group of formula III, IV or V, x, y and z are each 0-10, Z and Rf are each a 1-10C perfluoroalkyl, A is SO3M, COOM or SO2F, SO2F, CN, COF and COOR which are convertible into the former two groups when hydrolyzed, M is H or an alkali metal and R is a 1-10C alkyl, with 0.5- 50pts.wt. nonconductive finely divided inorganic substance of particle diameter 0.1-100mu (e.g., SiC) and forming the resulting mixture into a 20-100mu-thick membrane.

Description

[Detailed Description of the Invention] The present invention relates to a method for producing a fluorine-containing ion exchange resin membrane, and more specifically, it involves uniformly mixing inorganic fine particles of Takesada to form a film of a fluorine-containing ion exchange resin membrane. The present invention relates to an improved method for producing a fluorine-containing ion-exchange resin.

Conventionally, various electrolysis methods have been proposed using water, rice, or an aqueous solution such as an alkaline aqueous solution, an alkali halide, or an alkali carbonate aqueous solution.

In recent years, from the viewpoint of pollution prevention, the diaphragm method has replaced the mercury method as a method for obtaining caustic alkali and chlorine by electrolyzing such aqueous solutions, especially aqueous alkaline chloride solutions. A method using an ion exchange membrane has been put into practical use for the purpose of obtaining high yields.

On the other hand, in the electrolysis of yuzu from the viewpoint of energy saving, it is required to reduce the electrolytic voltage to an extremely low level, and various means have been taken to reduce the electrolytic voltage to mV. For example 1. The so-called 5P method involves electrolysis by bringing a gas- and liquid-permeable porous layer and an upper electrode into close contact with one side of a fluorine-containing ion-exchange resin membrane.
E (5 solid polymer electrolyte)
te) type basket tile method (see, for example, JP-A-58-52297, JP-A-52-78788, etc.) is known. In addition, a method of using a fluorine-containing ion exchange resin having at least one rough surface and arranging the rough surface toward the gruesome side (see Japanese Patent Application Laid-open No. 110786/1986, etc.) is also available. has been done. Furthermore, a method using a fluorine-containing ion-exchange resin having a gas- and liquid-permeable porous layer formed on its surface that does not act as m& is disclosed in JP-A-56-755.
It has been proposed in Publication No. 88, etc.

The present inventor unexpectedly discovered the following by forming a film by uniformly mixing inorganic fine particles such as silicon carbide and titanium oxide with a fluorine-containing ion exchange resin in a specific ratio. The blended film obtained by uniformly mixing inorganic fine particles can reduce the overburden pressure of electric oaks using the blended film. Furthermore, such a blend family has a y=plane,
This has the advantage that the hydrophilicity of the membrane increases and the mechanical strength of the membrane is significantly improved.

Thus, the present invention provides a method for producing a fluorine-containing ion exchange <g, r fat film, which comprises forming a film of a fluorine-containing ion exchange resin having an ion exchange group, in which inorganic The present invention provides a novel method for producing fluorine-containing ion exchange resins, which is characterized by forming a film by uniformly mixing 05 to 50 parts by weight of fine particles.

In the present invention, it is important to form a film by uniformly mixing inorganic fine particles with a fluorine-containing ion exchange resin in a specific proportion. The mixing ratio of inorganic fines is 10 parts of fluorine-containing ion exchange resin.
05 to 5014' parts per 0 parts by weight, preferably 6 to 8 parts by weight
Selected from the range of 0-fold violet. If the mixing ratio of the inorganic fine particles is too small, the above-mentioned effects such as reducing the electrolysis voltage in the present invention will be slight, and if it is too large, the various electrolytic performances of the fluorine-containing ion-combined membrane will tend to be impaired. As it increases,! There is also a drawback in that the electrolytic voltage increases. and,
It is important that the inorganic fine substances are mixed uniformly, and from the viewpoint of such uniform mixing, the particle size ai-to.

Imitation fine particles of micron, preferably 01-50 micron or diameter of 01-100 micron, preferably 01-50
Micron, length 1 micron-5mm Cl *Fine fiber is adopted.

There is no particular reason to limit the type of inorganic fine particles, but it may be determined depending on the purpose and conditions of use of the fluorine ion exchange resin membrane blended with these fine particles or fine fibers. It is desirable that That is, in total, inorganic fine materials are selected from the viewpoint of corrosion resistance for the polar liquid in which the specific blend film is used, and non-conductive materials are particularly preferred. And the representative? Kinmine as ll.

Examples include acetates, hydroxides, carbides, nitrides or mixtures thereof. Preferred specific examples include group ■-A of the periodic table (preferably silicon, germanium, tin, and lead), IV-BN (preferably tL<= titanium, zirconium, and hafnium), and group V-B (preferably tL<= titanium, zirconium, and hafnium). Preferably, niobium, tantalum), iron group metals (iron, cobalt, nickel),
Elements or alloys, oxides of chromium, manganese or boron,
Hydroxides, nitrides or carbides are used as corrosion resistant materials such as chlorine resistant.

As the inorganic fine particles in the present invention, ceramic particles having large hardness, excellent side-corrosion properties, and heat resistance are also used, and examples include not only oxide ceramics but also non-oxide ceramics. Examples include carbides, nitrides, silicides, borides, and (IIItc) compounds.

As carbide, HfC, TaC, ZrC, SiC, B4
C, WC, TiC.

CrC, UC, BeC, etc., but as silicon materials, Cr, M
Silicides such as OlW, Ti, Nb or Zr, and nitrides such as BN, Si3N4. TiN, AIN
As borides, T1, Zr, Hf, C
borides of e, Mo, W, Ta, Nb or La, and the borides include Fe5B, , Mob2f
Illustrated are: Among them, SiC, B, C, BN
, Si3N4, TiN, AIN, MoSi2
, LaB6, etc. are preferred specific examples.

Other inorganic y II in the present invention? −1 as J,
TiO2, ZrO,, Nb2O,, Ta2O,, Fe2
Examples include O3, Fe3O4, SnO2, and CeO2.

In the present invention, the fluorine-containing ion or substituted fat is preferably a 4dj fat made of a fluorine-containing polymer having an ion exchange group with a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a phenolic hydroxyl group, or the like.

As such a resin, it is preferable to use a resin having a copolymerization structure with a vinyl monomer such as tetrafluoroethylene or chlorotrifluoroethylene, or a fluorovinyl monomer containing an ion exchange group such as a sulfonic acid, carboxylic acid, or phosphoric acid group.

In particular, 1. of polymers consisting of the following structures (a) and (b)
,・use is preferable.

(a) (-CF2-CXX/ ÷ +
(0) + CF, -cx → xFi here
F, C1, H or -CF3T, X' is X or CF3
(CF, -)--, and at m tri, t -5, Y is sh from the next.

Z Rf Z, Rf z RfX, y
, :'z are both 0' to 10, and Z and Rf are -
F or a perfluoroalkyl group having 1 to 10 carbon atoms. Mata, A bar So, M,, -COOM
Also, -8o2F which can be converted into these groups by hydrolysis
.

CN, -COF or =coOR, M represents hydrogen or an alkali metal, and R represents an alkyl group having 1 to 1 o carbon atoms.

In the fluorine-containing ion exchange resin membrane of the present invention, the ion exchanger is preferably 0'5 to 4.0 milliton per gram dry resin, particularly 08 to zo milliton per gram dry resin. preferable. To give an ion-exchange weighing capacity,
Upper Mr: In the case of an ion exchange resin membrane consisting of a combination of offshore units (a) and (b), the subcombination age of ← is preferably 1 to 40 molt, particularly 8 to 40 molt. 25 molti is suitable.

The fluorine-containing ion-exchange resin membrane used in the present invention does not necessarily have to be formed from one type of polymer, nor does it need to contain only the ion-exchange groups of citrus. For example, two types of polymers may be used in combination as an ion exchanger, and an ion σ 1 tumor film using a combination of a weak acid exchange group such as a carboxylic acid group and a strong y4 exchange group such as a sulfonic acid group is used. It may be.

The inorganic fine particles and the fluorine-containing ion mixed side fat are uniformly mixed to form a film. The manufacturing h4 can be performed by conventionally known methods.

However, such a specific blend membrane can be reinforced with a non-woven fabric such as a cloth or net made of a fluorine-containing polymer such as polytetrafluoroethylene, a metal mesh, a porous body, etc., if necessary. . The thickness of the shaft friend membrane of the present invention is usually 20 to 500μ, preferably 50 to 400μ.

In the present invention, the uniform mixing of the inorganic fine particles and the fluorine-containing ion exchange resin and the production of Bψ are carried out by various means as described above. For example, using an aqueous dispersion, an organic solution, or a dispersion of a fluorine-containing ion-exchange resin, uniform mixing with inorganic fine particles can be carried out in a wet method, or such an organic solution or dispersion mixed with inorganic fine particles can be used. It is also possible to form a film using a casting method or the like.

Of course, it is also possible to form a film by employing a tri-blend method or by heat-melting a blended product. In addition to film formation by unskillful heating and melt molding, the fluorine-containing ion exchange resin may be prepared in an appropriate form of ion exchange group that does not cause decomposition of the ion exchange group it has, such as a carboxylic acid group. It is preferable to use the ester type, and in the case of a sulfonic acid group, it is preferable to use the -5o2F type. Furthermore, the blend can be heated and melt-molded in advance to form pellets, and the pellets can be formed into B4 by extrusion molding, press molding, or the like.

Although specific blend membranes are used extensively in various military campaigns, any type of positive force may be used for such removal. For example, porous electrodes such as perforated plates, mesh or expanded metal are used. As a narrow gap electrode, the long axis is LO~10'', the short axis is 05~10'', and the wire diameter is 01~L8''.
, expanded metal with a porosity of 80 to 90% is exemplified. In addition, a plurality of plate-like %[ may also be used, but it is preferable to use *t= of a plurality of plates with different porosity and use the one with the smaller porosity on the side closer to the membrane.

As the anode material, KFI platinum group metal, its conductive oxide or its conductive reduced tobide, etc. are used, while as the cathode, platinum group gold pine, its conductive oxide, or iron group metal, etc. are used. 0 Examples of platinum group metals include platinum, rhodium, ruthenium, palladium, and iridium, and examples of iron group metals include iron, conorct, nickel, Raney nickel, stabilized Raney nickel, stainless steel, and alkali-etched stainless steel (%'). Kosho 54-19229
Publication No.), Raney nickel plated cathode (Unexamined Japanese Patent Publication No. 54-1
12785) and Rodan nickel plating gruesomeness (Japanese Patent Application Laid-Open No. 115676/1984).

If a porous electrode is used, the electrode can be formed from the anode or the cathode-forming material itself. However, when platinum group metals or conductive fluorides thereof are used, it is preferable to coat the surface of an expanded valve metal such as titanium or tantalum with these substances.

In the case of arranging electrodes in the present invention, the electrodes may be arranged in contact with the specific blend film, or may be arranged at appropriate intervals. Rather than firmly pressing the electrode against the ion exchange membrane surface, the electrode is pressed firmly against the ion exchange membrane surface, for example by 0 to 2.
The OIcy/cdl is preferably pressed gently.

The electric j911' cypress using the blend membrane of the present invention may be of a monopolar type or a bipolar type. In addition, the materials that make up the electrolytic cell are
For example, in the case of electrolysis of an alkaline chloride water bath, a material resistant to alkaline chloride and chlorine is used in the anode chamber, such as valve metal or titanium, and in the case of the cathode chamber, hydroxide is used. Iron, stainless steel or nickel, which are resistant to alkali and hydrogen, are used.

As the process conditions for electrolyzing an aqueous alkali chloride solution using the blend membrane of the present invention, known conditions can be adopted. For example, the anode is preferably 25 to aO (N
), and water or diluted alkali hydroxide is supplied to the cathode, preferably at 80°C to 120°C.
U, current density 10-100 A/eLm. In such a case, heavy metal ions such as calcium and magnesium in the aqueous alkali chloride solution cause deterioration of the ion exchange membrane, so it is preferable to keep them as small as possible. Furthermore, an acid such as hydrochloric acid can be added to the aqueous alkali chloride solution in order to prevent the generation of oxygen as much as possible.

Hereinafter, the use of the specific blend membrane of the present invention has been clearly explained mainly using the example of ~1 solution of aqueous alkali chloride solution, but it is also applicable to the electrolysis of water, hydrochloric acid (hydrochloric acid, hydrobromic acid), and alkali carbonate. Of course, it can also be applied in the same way. It can also be applied as a diaphragm in various one-part decomposition reactions of organic compounds using ion exchange membranes.

Next, the embodiments of the present invention will be explained in more detail, but it goes without saying that the present invention is not limited to the above description. Note that the parts in the examples are heavy electrical parts unless otherwise specified.

Example 1 One part of iron oxide powder with a particle size of 25μ or less, a copolymer of tetrafluoroethylene and CF, =CFO (CF, ), C00CR8, with an ion exchange capacity of 148 mt3Q/'
j 9 parts of ion exchange resin powder, which is a dry resin, and 50 parts of methanol were mixed for 1 hour using an automatic mortar, and then dried to obtain a mixed powder consisting of iron dioxide powder and ion exchange fat powder. Ta.

The mixed powder was formed into a membrane using a press molding machine at a temperature of 220°C to obtain an ion exchange membrane having a float of 300μ.

The ion exchange membrane was immersed in a 25 parts mk 2% caustic soda aqueous solution at 90° C. for 16 hours to hydrolyze the ion exchange membrane.

The anode side of the ion-exchange membrane is made of titanium expanded metal (breadth 15", long diameter 5B+1").

A positive membrane coated with a solid solution of ruthenium oxide, iridium oxide, and titanium oxide and having a low chlorine pressure was added to the cathode side of the ion-exchange membrane. ) in a 52% caustic soda aqueous solution at 150° C. for 52 hours to have a low hydrogen overvoltage was contacted under pressure, and a 5 N-NaCl aqueous solution was supplied to the anode and water was supplied to the cathode chamber. Electrolysis was carried out at 90° C. while maintaining the sodium chloride concentration in the anode chamber at 4N and the caustic sodium concentration in the anode solution at 85% by weight, and the following results were obtained.

Current density (A/d) Falling voltage (g) 2 0
2.844 0
82B 6 0 860 In addition, the current efficiency of caustic soda production at a current density of 40 A/da was 92%. Furthermore, the current density is 40 A
When electrolysis was continued for one month at /d@', the cell voltage remained almost constant.

Comparative Example In Example 1, 11/
An LjIh tank was assembled and a saline solution was electrolyzed to obtain the following results.

Current density (A/d m”) Cell voltage (v) 2 0
a074 0
a5060 a90 Further, the current efficiency for caustic soda production at a current density of 40 A/am was 94 chi.

Example 2 A film was formed in the same manner as in Example 1 except that 05 parts of iron oxide powder and 35 parts of ion exchange resin powder were used in Example 1, and electrolysis was performed under the same conditions to obtain the following results. Ta.

Current casing (A/d) Rated voltage (V) 20 2.95 40 a87 60 a72 In addition, the flow efficiency of caustic powder generation at an initial current of 40 A/drrl was 92.5%.

Example 8 Electrolysis was carried out in the same manner and under the same conditions as in Example 1, except that zirconium oxide with a particle size of 25 μm or less was used instead of the iron oxide powder in Example 1, and the following results were obtained.

Electricity & Density (A/di") 20 2.92 4 0 a80 6 0 a64 Also, IM #i, density g 4 QA, 'a77/ I/C
The current efficiency for the generation of caustic salt was 92.

Implementation time 4 A real 7Mf 11t odor circle, an average fiber length of 16g, and an electric current was applied in the same manner and under the same conditions as in Example 1, except that an M8 micron zirconium oxide fiber was used all around. , I got the following results.

Current c&j degree (A/eLm) Cell voltage (g) 20
2.96 40 a40 60 884 In addition, the current efficiency of caustic soda generation at a current density of 40 A/d was 92.5%.

Claims (1)

[Scope of Claims] A method for producing a Datura elementary ion exchange resin membrane comprising forming a film of a fluorine-containing ion exchange side fat having an ion exchange group, wherein the fluorine-containing ion exchange resin 1003iilt
1) Method for manufacturing a fluorine-containing ion-exchange membrane by uniformly mixing 6 to 50 parts by weight of fine particles α per part. 2. The manufacturing method according to item 1 of the scope of Patent M, wherein the inorganic fine particles are fine particles having a particle size of 01 to 100 microns. 1. The manufacturing method according to claim 1, wherein the inorganic fine particles are fine navy blue fibers having a diameter of 1 to 100 microns and a length of 1 micron to 5 strips. The method according to claim 1, wherein the ion exchange group is a carboxylic acid type, sulfonic acid type, or phosphoric acid type ion exchange group.