JPS5811791A - Method for providing flare on ion exchange film - Google Patents

Abstract

PURPOSE:To provide a flare on an ion exchange film very easily, by contact- placing a cylindrical body capable of being deformed having larger rigidity than a cylindrical ion exchange film, on the inside surface of this ion exchange film, and press-inserting a heated tapered force die from the opening part of this cylindrical body. CONSTITUTION:A sheet-like cation exchange film is made to contact with the inside surface of a cylindrical ion exchange film 1 which has been manufactured in the shape of a cylinder by a junction method, etc., and a cylindrical body 2 which has larger rigidity than this film 1 and can be deformed is placed. Subsequently, a tapered force die 6 which has been heated to the extent that the film 1 can be softened and deformed is inserted into its inside surface from the tip of the opening part of the film 1, the film 1 is gradually softened through the cylindrical body 2, the film 1 is spread out by force to the outside by the tapered part, and a flare is formed. In this regard, 3, 4, 5 and 7 in the figure denote a core, an outside metallic mold, an upper metallic mold, and a cylindrical body having the same quality as the cylindrical body 2 provided on the outside of the film 1, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for flaring an ion exchange membrane.

Ion exchange membranes are installed in various devices and are widely used for adsorption of impurities, separation of selectively passing only specific ions, and the like.

Among these, cation exchange membranes have been attracting particular attention in recent years as diaphragms for chloralkali electrolysis. Depending on the device, the ion exchange membrane is often used as a cylindrical body, and it is often convenient to provide a cylindrical opening with a 7-reare when it is attached to the device. For example, in the case of a chlor-alkali electrolytic cell in which the electrode shape is finker-like, so-called diamond, dome tank, or granol electrolytic cell, when a cation exchange membrane is attached to these electrodes, the shape of the cation exchange membrane is cylindrical or open on one side. It is necessary to have a bag-like shape, and if the opening of the cylindrical or bag-shaped cation exchange membrane is provided with a flare, it is a cylindrical or bag-shaped cation exchange membrane that can be loaded into an electrolytic cell. However, it is very difficult to join the flare to the opening of this.

The inventors of the present invention have conducted extensive studies on how to easily process a cylindrical or bag-shaped cation exchange membrane to provide flares in an extremely simple manner, and as a result, they have arrived at the present invention. A deformable cylindrical body that is in contact with the ion exchange membrane and has a greater rigidity is disposed on at least the inner surface of the ion exchange membrane, and a tapered cylindrical body heated from the cylindrical opening of the ion exchange membrane is provided. The gist of this method is to provide a flare in an ion exchange membrane, which is characterized by press-fitting a push die and pushing the opening outward.

As the ion exchange membrane used in the present invention, a hydrocarbon membrane having an ion exchange group such as a carbonic acid group, a sulfonic acid group, or a phosphonic acid group, or a fluorine-containing hydrocarbon membrane can be used.

Among the above, perfluorocarbon resin membranes having carboxylic acid groups, sulfonic acid groups, and phosphonic acid groups as ion exchange groups are suitable as ion exchange membranes for halogenated alkali electrolysis.

Furthermore, the ion exchange membrane used in the present invention does not contain any of the ion exchange membranes described above. It also includes a processed membrane in which a gas- and liquid-permeable porous layer that does not function as an electrode is provided on at least one surface of the membrane.

The present invention will be explained based on illustrated drawings.

It is a sketch of an exchange membrane.

FIG. 2 is an example of a cross-sectional explanatory view of a state in which a cylindrical ion exchange membrane is set in an apparatus for carrying out the method of the present invention.

The cylindrical ion-exchange membrane 1 shown in FIG. 1 can be produced by forming a sheet-like cation-exchange membrane into a V-cylindrical shape by a bonding method or the like.

In FIG. 2, 1 is a cylindrical ion exchange membrane, and 2 is a deformable cylindrical body that is more rigid than the ion exchange membrane and is placed in contact with the inner surface of the cylindrical ion exchange membrane. 3 is the core, 4
5 is an outer mold, and 5 is an upper mold. The upper mold 5 is further provided with a tapered push die 6 having a built-in heating device on its lower surface. 7 is a cylindrical body of the same quality as the cylindrical body 2 provided outside the cylindrical ion exchange membrane.

Now, as shown in Fig. 2, when the push die is heated to such an extent that the ion exchange membrane can be softened and deformed, and it is inserted into the inner surface of the cylindrical ion exchange membrane, from the opening tip of the ion exchange membrane)
IF primary softening occurs, and the tapered part of the push die pushes outward and deforms, and eventually this pushed and spread part forms a flare.

In this case, it is necessary that a deformable cylindrical body having greater rigidity than the ion exchange membrane be disposed on at least the inner surface of the ion exchange membrane so as to be in contact with the inner surface.

Ion exchange groups are usually used with a thickness of several hundred microns, and they do not have self-supporting properties, and when deformed from the upper end of the opening during the above operation, excessive deformation occurs, i.e.,
Because the inner surface of the ion-exchange membrane is at a high temperature, the ion-exchange membrane expands more, causing the flare to become circular or wavy.

For this reason, a cylindrical body that is deformable but has greater rigidity than the ion exchange membrane and can prevent excessive deformation of the ion exchange membrane is placed on the outside of the cylindrical ion exchange membrane. is necessary.

As mentioned above, the material for this cylindrical body is not particularly limited as long as it is deformable and has greater rigidity than the ion exchange membrane, but it is more preferable that it It is desirable that it has good mold releasability and that it does not easily adhere to the ion exchange membrane. As a result of extensive research, the present inventors discovered that glass fiber fabric (
It has been found that a material obtained by impregnating polytetrafluoroethylene (glass cloth) is most preferable as it has all of the above-mentioned properties. .

Furthermore, it is preferable that such a cylindrical body be disposed on the outer surface of the cylindrical ion exchange membrane so as to be in contact therewith. This cylindrical body placed on the inner surface also acts as a mold release agent for the core.

It is preferable to use a thick inner cylindrical body for these two cylindrical bodies. The reason for this is that the inner cylindrical body has the role of converting the descending blade of the push die into a force for pushing and spreading the ion exchange membrane, and therefore needs to have greater rigidity than the outer cylindrical body.

Further, the width of the flare is preferably kept at about 10 to 20 meters because the wider the flare, the thinner the tip of the flare becomes.

Next, the present invention will be explained in detail with reference to Examples.

Example 1 Tetrafluoroethylene and CF2 = CFO (CF2) with a width of 60 mm, a length of 890 mm, a height of SOO, and a cross section of the opening (6 o sea bream x sc + omm) having an almost oval shape and a thickness of 280 μ.
A cylindrical cation exchange membrane made of a copolymer of C00CHs was provided with a flare in the following manner.

The outer surface of the cylindrical cation exchange membrane is 250μ thick flow glass (Crow & I11 textile impregnated with polytetrafluoroethylene), and the inner surface is 350μ thick flow glass that is in close contact with the cation exchange membrane. As shown in FIG. 9, the tapered part of the upper mold is heated to 200°C, inserted into the cylindrical opening, and pressurized to form 15III+ flared cations. An exchange membrane cylindrical body was molded.

At the locations located at both ends of the above opening of the flow glass,
Cuts with a depth of 20 mm were pre-prepared at the top at intervals of 5 to 10 W1, so the flow glass spreads smoothly, and also the release from the mold and the separation of the flow glass and the cation exchange membrane are smooth. I was able to do that.

Example 2 In place of the cation exchange membrane cylinder of Example 1, a cation exchange membrane cylinder provided with a porous layer manufactured as follows was used.

2% by weight (7) 2.5 parts of an aqueous dispersion containing 7.0% by weight of polytetrafluoroethylene (hereinafter referred to as FTFB) with a particle size of 1 μ or less for 10 parts of a thickener in an aqueous methylcellulose solution; Titanium oxide powder with a particle size of 25μ or less 5
After thorough mixing in advance, 2 parts of isopropyl alcohol and 1 part of cyclohexanol were added and kneaded again to obtain a paste.

The paste was applied to a printing plate with a mesh number of 200 and a 60μ thick stainless steel screen with an 8μ thick screen mask underneath, and a polyurethane squeegee, until the ion exchange capacity of the printing substrate was 1. .43 m
eq /,! i + dry resin, polytetrafluoroethylene with a thickness of 210μ and CFz = CFO (CF2),
Screen printing was performed on one side of an ion exchange membrane made of a C00CHsO copolymer in a size of 800 mm x 1900 pieces.

The printed layer obtained on one side of the ion exchange membrane was dried in air to solidify the paste. On the other hand, titanium oxide having a particle size of 25 μm or less was screen printed on the other side of the ion exchange membrane in exactly the same manner. After that, the temperature is 140
After the printed layer was pressure-bonded to the ion membrane at a molding pressure of 30 kg/6I at 90 DEG C., it was immersed in a 25% by weight aqueous sodium hydroxide solution to hydrolyze the ion membrane and elute methyl cellulose.

The titanium oxide/layer obtained on the ion exchange membrane has a thickness of 20 μm.
It had a porosity of 70 cm and contained titanium oxide at 1.5 cm/d.

This was joined together at sides of 800 m+n to obtain a cylindrical body with an opening cross section of approximately 60 wn x 890 wn and a height of 800 wn.

This cylindrical body was provided with a flare in the same manner as in Example 1.

The results were the same as in Example 1, where release from the mold and separation from the flow glass were smooth, and a good flared ion exchange membrane cylinder was obtained.

[Brief explanation of the drawing]

FIG. 1 is a sketch of a cylindrical ion exchange membrane before providing flares. FIG. 2 is an explanatory cross-sectional view of a cylindrical ion exchange membrane set in an apparatus for carrying out the method of the present invention.

Claims (1)

[Claims] A deformable cylindrical body that is in contact with the ion exchange membrane and has a greater rigidity is disposed on at least the inner surface of the cylindrical ion exchange membrane, and the taper is heated from the cylindrical opening of the ion exchange membrane. A method for providing a flare in an ion-exchange membrane, characterized by compressing a press die with a holder and pushing the opening outward.