JP2021053571A - Ion exchanger sheet and method for production thereof - Google Patents

Abstract

To provide an ion exchanger sheet capable of accelerating an ion exchange rate while enlarging an ion exchange capacity, and to provide a method for production of the sheet.SOLUTION: An ion exchanger sheet 1 has an ion exchanger capable of removing the impurity ions and for more detail, has a fiber layer 1a comprising a sheet-like fiber containing the ion exchanger and an ion exchanger layer 1b formed on the outer peripheral face of the fiber layer 1a in a porous mode. The ion exchanger sheet is obtained through: a sheet-making process S1 of forming a sheet-like fiber by following a papermaking technique; an impregnation process S2 of forming the fiber layer containing the ion exchanger by making the sheet-like fiber obtained in the process S1 impregnate with an impregnation liquid including the ion exchanger; and a heating process S3 of forming an ion exchanger layer 1b comprising the ion exchanger formed in a porous mode in the outer peripheral face of the fiber layer 1a by heating and drying the fiber layer obtained by the process S2.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ion exchanger sheet having an ion exchanger capable of removing impurity ions and a method for producing the same.

Recently, various proposals have been made for an ion exchange filter having an ion exchanger for removing impurity ions in a liquid and for softening industrial water or purifying drinking water, cooling water for vehicles, etc. For example, an ion exchange resin obtained by molding an ion exchanger into granules, an ion exchange fiber in which an ion exchanger is fixed to a fiber, and the like have been proposed. Among these, as the ion exchange fiber, as disclosed in Patent Document 1 and the like, those formed by fixing an ion exchange layer to the surface of the core fiber can be mentioned.

International Publication No. 2018/043462

However, the above-mentioned prior art has the following problems.
In the granular ion exchange resin, the ion exchange capacity per volume is relatively high, but in order to increase the ion exchange rate, it is necessary to reduce the diameter of each ion exchange resin, so that the ion exchange resin can be recovered. In addition to becoming difficult, there is a problem that the ion exchange resin flows out together with the liquid and the ion exchange effect is lowered.

Further, in the ion exchange fiber in which the ion exchanger is fixed to the fiber, by using the fiber as a non-woven fabric, the surface area is increased due to the pores of the non-woven fabric, and the ion exchange rate can be increased. Since the ion exchanger is fixed, there is a problem that the overall ion exchanger density is reduced and the ion exchange capacity per volume cannot be increased.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ion exchanger sheet capable of increasing the ion exchange rate while increasing the ion exchange capacity and a method for producing the same.

The invention according to claim 1 is an ion exchanger sheet having an ion exchanger capable of removing impurity ions, the fiber layer made of sheet-like fibers containing the ion exchanger, and the outer periphery of the fiber layer. It is characterized by having an ion exchanger layer made of the ion exchanger formed on a surface and formed porously.

The invention according to claim 2 is characterized in that, in the ion exchanger sheet according to claim 1, the ion exchanger layer is formed on either the front surface or the back surface of the fiber layer.

The invention according to claim 3 is the ion exchanger sheet according to claim 1 or 2, wherein the fiber layer has a thickness dimension of 0.05 mm or more and 0.3 mm or less, and the ion exchanger layer. Is characterized by having a thickness dimension of 0.01 mm or more and 0.1 mm or less.

The invention according to claim 4 is the ion exchanger sheet according to any one of claims 1 to 3, wherein the ion exchanger layer has a thickness of 0.1 or more and 0.5 or less of the total thickness dimension. It is characterized by being dimensioned.

The invention according to claim 5 is the ion exchanger sheet according to any one of claims 1 to 4, wherein the ion exchanger is fixed to the fibers of the fiber layer with an organic binder or an inorganic binder. It is characterized by.

The invention according to claim 6 is characterized in that, in the ion exchanger sheet according to any one of claims 1 to 5, the fibers constituting the fiber layer are made of hydrophilic fibers.

The invention according to claim 7 is the ion exchanger sheet according to any one of claims 1 to 6, wherein the ion exchanger is made of an inorganic powder.

The invention according to claim 8 is a method for producing an ion exchanger sheet having an ion exchanger capable of removing impurity ions, which is obtained by a fabrication step of forming sheet-like fibers by fabrication and the fabrication step. By impregnating the sheet-shaped fibers with an impregnating solution containing the ion exchanger, an impregnation step of forming a fiber layer containing the ion exchanger and a fiber layer obtained in the impregnation step are heated and dried. It is characterized by having a heating step of forming an ion exchanger layer composed of the ion exchanger formed porously on the outer peripheral surface of the fiber layer.

The invention according to claim 9 is the method for producing an ion exchanger sheet according to claim 8, wherein in the impregnation step, the impregnating solution is added to the fiber obtained in the making step to vacuum impregnate or vacuum impregnate. It is a feature.

The invention according to claim 10 is the method for producing an ion exchanger sheet according to claim 8 or 9, wherein in the heating step, the fiber layer containing the ion exchanger is heated at a predetermined temperature for a predetermined time. , The ion exchanger layer is formed on the outer peripheral surface of the fiber layer.

According to the invention of claim 1, a fiber layer made of sheet-like fibers containing an ion exchanger and an ion exchanger layer made of an ion exchanger formed on the outer peripheral surface of the fiber layer and formed porously. Therefore, the ion exchange rate can be increased while increasing the ion exchange capacity.

According to the invention of claim 2, since the ion exchange body layer is formed on either the front surface side or the back surface side of the fiber layer, the ion exchange characteristics can be arbitrarily changed between the front surface side and the back surface side of the fiber layer. The balance between the ion exchange capacity and the ion exchange rate can be adjusted as appropriate.

According to the inventions of claims 3 and 4, the fiber layer has a thickness dimension of 0.05 mm or more and 0.3 mm or less, and the ion exchanger layer has a thickness dimension of 0.01 mm or more and 0.1 mm or less. Or, since the ion exchanger layer has a thickness dimension of 0.1 or more and 0.5 or less of the total thickness dimension, the ion exchange capacity can be increased and the ion exchange rate can be increased. Moreover, the moldability of the ion exchanger sheet can be improved.

According to the invention of claim 5, since the ion exchanger is formed by being fixed to the fibers of the fiber layer with an organic binder or an inorganic binder, the ion exchanger can be suppressed from falling off from the fibers of the fiber layer, and the ion exchange effect can be maintained for a long period of time. Can be sustained over.

According to the invention of claim 6, since the fibers constituting the fiber layer are made of hydrophilic fibers, the affinity between the liquid containing impurity ions and the fibers of the fiber layer is improved, and the ion exchanger contained in the fibers is improved. It is possible to make good contact of the liquid with respect to the fiber.

According to the invention of claim 7, since the ion exchanger is composed of an inorganic powder, it is possible to suppress absorption of a liquid containing impurity ions and swelling, and ion exchange per volume due to swelling. It is possible to avoid the capacity becoming small.

According to the invention of claim 8, the ion exchanger is formed by impregnating the sheet-shaped fiber obtained in the fabrication step with an impregnating solution containing the ion exchanger in the fabrication step of forming the sheet-shaped fiber by the fabrication. By heating and drying the impregnation step of forming the contained fiber layer and the fiber layer obtained in the impregnation step, an ion exchanger layer composed of an ion exchanger formed porously on the outer peripheral surface of the fiber layer is formed. Since it has a heating step of forming, it is possible to easily obtain an ion exchanger sheet capable of increasing the ion exchange rate while increasing the ion exchange capacity.

According to the invention of claim 9, in the impregnation step, the impregnating solution is added to the fibers obtained in the papermaking step to impregnate the fibers with vacuum or reduced pressure, so that a fiber layer containing the ion exchanger uniformly can be obtained. ..

According to the invention of claim 10, in the heating step, the fiber layer containing the ion exchanger is heated at a predetermined temperature for a predetermined time to form an ion exchanger layer on the outer peripheral surface of the fiber layer. By arbitrarily adjusting the heating time, a desired thickness dimension and a porous ion exchanger layer can be obtained.

Schematic cross-sectional view showing the inside (fiber layer and ion exchanger layer) of the ion exchanger sheet according to the embodiment of the present invention. Flow chart showing the manufacturing method of the ion exchanger sheet Schematic diagram showing the details of the heating process in the method for manufacturing the ion exchanger sheet. Ion exchanger sheet showing the state after the processing step in the manufacturing method of the ion exchanger sheet Schematic cross-sectional view showing the inside (fiber layer and ion exchanger layer) of the ion exchanger sheet according to another embodiment of the present invention. Micrograph showing the internal state of the ion exchanger sheet

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The ion exchanger sheet 1 according to the present embodiment is in the form of a sheet having an ion exchanger capable of removing impurity ions contained in the liquid, and as shown in FIGS. 1 and 6, ion exchange with the fiber layer 1a. It is configured to have a body layer 1b. According to the ion exchanger sheet 1, the impurity ions (specific ions) can be captured and removed by passing a liquid containing the impurity ions, so that the industrial water can be softened or drinking water or a vehicle. It is possible to purify the cooling water for use.

The fiber layer 1a is made of a sheet-shaped cellulose fiber containing an ion exchanger, and has a thickness dimension of 0.05 mm or more and 0.3 mm or less, preferably about 0.15 mm. .. More specifically, the fiber layer 1a according to the present embodiment is made of pulp such as cellulose and is formed into a sheet shape (paper shape) by a papermaking method (papermaking method), and has a porosity (Canadian standard). The freeness) is 700 to 740 (mL), and the porosity (measured by the mercury intrusion method) is about 65%.

Further, as a result of the experiment, it was found that ^{the ion exchange capacity can be set to 5.0 (meq / cm 3} ) by setting the fiber layer 1a to 0.3 mm or less. This unit (meq / cm ³ ) indicates the amount of impurity ions that can be captured by the 1 cm ^{3 ion exchanger.} In addition to cellulose, hydrophilic fibers such as cotton, wool and silk can be used for the fiber layer 1a.

The ion exchanger applied in the present embodiment is made of an inorganic powder, and for example, zirconium phosphate, zeolite, hydrotalcite, metal oxide, or the like can be used. This ion exchanger is fixed to the fibers of the fiber layer 1a by a binder such as urethane resin. That is, as shown in FIG. 6, the ion exchanger contained in the fiber layer 1a is fixed to the fiber d formed in a mesh shape by the binder. The binder may be either an organic binder or an inorganic binder, and in addition to the urethane resin, an epoxy resin, a polyester resin, an acrylic resin, an alumina sol, or the like can be used.

The ion exchanger layer 1b is composed of an ion exchanger formed on the outer peripheral surface (front surface or back surface) of the fiber layer 1a and formed porously, and in the present embodiment, as shown in FIGS. It is formed only on the back surface of the layer 1a. As shown in FIG. 6, the ion exchanger layer 1b does not have fibers and is composed of a porous ion exchanger having a thickness dimension of 0.01 mm or more and 0.1 mm or less. It is preferably configured to have a thickness dimension of about 0.025 mm.

However, when the ion exchanger layer 1b has an excessive thickness dimension, it becomes difficult for the liquid containing impurity ions to permeate to the fiber layer 1a, the ion exchange effect is lowered, and the ion exchanger layer 1b does not contain fibers, so that it is in the form of a sheet. Since it becomes difficult to maintain the shape of the above, it is preferable that the thickness dimension is 0.1 or more and 0.5 or less of the total thickness dimension (thickness dimension of the entire ion exchange member 1).

Since the ion exchanger layer 1b is made of a porous ion exchanger, a liquid containing impurity ions can be permeated inside, and the fiber layer 1a can be allowed to reach the inside. As a result, the impurity ions can be captured by both the ion exchanger in the fiber layer 1a and the ion exchanger in the ion exchanger layer 1b. Although the ion exchanger layer 1b according to the present embodiment is formed only on the back surface (lower surface of FIG. 1) of the fiber layer 1a, it may be formed only on the front surface (upper surface of FIG. 1), or , As shown in FIG. 5, may be formed on both sides (front surface and back surface) of the fiber layer 1a, respectively.

Next, a method for manufacturing the ion exchanger sheet 1 according to the present embodiment will be described with reference to the flowchart of FIG.
First, a pulp material such as cellulose is formed into a sheet (paper) by a papermaking method to obtain a sheet-like fiber having a thickness of 0.05 mm or more and 0.3 mm or less (papermaking step S1). In this papermaking process, the fibers obtained by papermaking do not contain an ion exchanger and are in a so-called raw paper state.

Then, the sheet-shaped fiber obtained in the fabrication step S1 is impregnated with an impregnating solution containing an ion exchanger to obtain a fiber layer containing the ion exchanger (impregnation step S2). In this impregnation step S2, when the binder is a urethane resin, an ion exchanger made of an inorganic powder is dispersed in a solvent made of acetone (ketones, esters, water, etc. may be used depending on the type of binder). An impregnating solution is prepared by mixing and stirring the above-mentioned urethane resin, and the impregnating solution is added to the fibers obtained in the fabrication step S1 to impregnate the fibers.

Here, in the impregnation step S2 according to the present embodiment, the above-mentioned impregnation liquid is added to the fibers obtained in the papermaking step S1 to vacuum impregnate or vacuum impregnate. By performing vacuum impregnation or vacuum impregnation in this way, the impregnating liquid can be contained while allowing the air in the fiber to escape to the outside, and the ion exchanger can be contained throughout the fiber. The fiber obtained in the papermaking step S1 may contain an ion exchanger by an impregnation different from vacuum impregnation or vacuum impregnation or another method.

Then, the fiber layer obtained in the impregnation step S2 is heated and dried to form an ion exchanger layer composed of an ion exchanger formed porously on the outer peripheral surface (back surface in the present embodiment) of the fiber layer 1a. 1b is formed (heating step S3). In this heating step S3, the fiber layer containing the ion exchanger is placed on a hot plate or a net in an oven and heated at a predetermined temperature for a predetermined time to form an outer peripheral surface (back surface) of the fiber layer 1a. It is a step of forming the ion exchanger layer 1b.

More specifically, as shown in FIG. 3A, the fiber layer obtained in the impregnation step S2 (since the dry-cured ion exchanger layer 1b was not formed before heating, the fiber layer was formed for convenience. (Fiber body 2 is used to distinguish it from 1a) is placed on a Teflon (registered trademark) sheet 3. At this time, the inside of the fiber body 2 contains the ion exchanger, the binder and the curing agent impregnated in the impregnation step S2, and the powder ion exchanger adheres to the front surface and the back surface of the fiber layer. The high-concentration layers 2a and 2b in the state are formed, respectively. When the fiber body 2 is placed on the Teflon sheet 3, the entire fiber body 2 has a thickness dimension of t1.

Subsequently, as shown in FIG. 3B, a separate Teflon (registered trademark) sheet 4 is pressed from the upper surface of the fiber body 2 and sandwiched between the Teflon sheet 3 and the Teflon sheet 3, whereby the thickness of t2 (t2 <t1) is increased. After forming a flat fiber body 2 having a vertical dimension, the Teflon sheet 4 on the upper surface is peeled off as shown in FIG. As a result, the high-concentration layer 2a on the upper surface of the fiber body 2 is peeled off together with the Teflon sheet 4, and the entire thickness is set to t3 (t3 <t2).

In this state, the fiber body 2 is placed on a hot plate or a net in an oven via a Teflon sheet 3 and heated at a predetermined temperature (for example, about 60 ° C.) for a predetermined time (for example, about 30 minutes). The solvent evaporates from above the fiber body 2 (the surface from which the Teflon sheet 4 is peeled off) and dries, and the ion exchanger is fixed to the fibers constituting the fiber body 2 with a binder to form the fiber layer 1a. The high-concentration layer 2b is dried and solidified to form the ion exchanger layer 1b. As a result, the ion exchanger sheet 1 as shown in FIG. 1 can be obtained.

As described above, the ion exchanger 1 obtained through the papermaking step S1, the impregnation step S2, and the heating step S3 is processed into a desired shape by the processing step S4. In the present embodiment, the ion exchanger sheet 1 is cut into strips and rolled into a roll as shown in FIG. 4 to form the final shape. If the roll-shaped ion exchanger sheet 1 is inserted into, for example, a polyester mesh bag or the like and used, it is possible to prevent contamination or the like from infiltrating into the liquid.

A mesh made of, for example, polyester or the like may be attached to the front surface or the back surface of the ion exchanger sheet 1 cut into strips, and the mesh may be rolled into a roll shape to obtain the final shape. In this case, since the liquid containing the impurity ions can be satisfactorily passed through the water, the ion exchange effect can be further enhanced. Further, the ion exchanger 1 may be formed into a honeycomb structure, or a plurality of the ion exchangers 1 may be overlaid and formed.

According to the ion exchange sheet 1 manufactured as described above, as a result of experiments, it has a high ion exchange capacity of about ^{5.0 meq / cm 3} and a high ion exchange rate of about ^{60 μmol / hour / cm 3.} in the case of using are (conventional granular ion-exchange resin, 2.2 meq / cm ³ order of the ion exchange capacity, 30μmol / hour / cm ³ order of the ion exchange rate, in the case of using the conventional ion exchange fibers, Ion exchange capacity of about 3.0 meq / cm ^{3) was found.} Therefore, according to the ion exchanger sheet 1 of the present embodiment, it was confirmed that both a high ion exchange capacity and a high ion exchange rate can be achieved at the same time.

According to the present embodiment, the fiber layer 1a made of sheet-like fibers containing an ion exchanger and the ion exchanger layer 1b made of an ion exchanger formed on the outer peripheral surface of the fiber layer 1a and formed porously. Therefore, the ion exchange rate can be increased while increasing the ion exchange capacity. That is, since the ion exchange area can be improved by utilizing the pores in the fiber layer 1a, it contributes to the improvement of the ion exchange rate and the filling rate (density) of the ion exchanger per volume in the ion exchanger layer 1b is increased. Since it can be improved, it can contribute to the improvement of the ion exchange capacity.

Further, since the ion exchange body layer 1b according to the present embodiment is formed on either the front surface side or the back surface side of the fiber layer 1a, the ion exchange characteristics can be arbitrarily changed between the front surface side and the back surface side of the fiber layer 1a. The balance between the ion exchange capacity and the ion exchange rate can be adjusted as appropriate. In particular, in the present embodiment, the solvent can be evaporated in the heating step S3 by utilizing the surface on which the ion exchanger layer 1b is not formed.

Further, the fiber layer 1a according to the present embodiment has a thickness dimension of 0.05 mm or more and 0.3 mm or less, and the ion exchanger layer 1b has a thickness dimension of 0.01 mm or more and 0.1 mm or less. Or, since the ion exchanger layer 1b has a thickness dimension of 0.1 or more and 0.5 or less of the total thickness dimension of the ion exchanger sheet 1, the ion exchange rate can be increased while increasing the ion exchange capacity. It can be increased, and the formability of the ion exchanger sheet 1 (for example, bending workability when rolling) can be improved.

Furthermore, since the ion exchanger according to the present embodiment is fixed to the fibers of the fiber layer 1a with an organic binder or an inorganic binder, the ion exchanger can be suppressed from falling off from the fibers of the fiber layer 1a to obtain an ion exchange effect. It can be sustained for a long period of time. Further, since the fibers constituting the fiber layer 1a are made of hydrophilic fibers, the affinity between the liquid containing impurity ions and the fibers of the fiber layer 1a is improved, and the liquid is brought into contact with the ion exchanger contained in the fibers. It can be done well.

In addition, since the ion exchanger according to the present embodiment is composed of an inorganic powder, it is possible to suppress absorption of a liquid containing impurity ions and swelling, and the ion exchange capacity per volume due to swelling. Can be avoided from becoming smaller. Further, since the ion exchanger is made of an inorganic powder, the porous ion exchanger layer 1b can be easily formed.

Further, the fiber layer 1a containing the ion exchanger is obtained by impregnating the sheet-shaped fiber obtained in the making step S1 with the impregnating solution containing the ion exchanger in the making step S1 for forming the sheet-shaped fiber by the making. The fiber layer (fiber body 2) is formed by heating and drying the impregnation step S2 for forming (fiber body 2 before heat drying) and the fiber layer 1a (fiber body 2) obtained in the impregnation step S2. Since it has a heating step S3 for forming an ion exchanger layer 1b made of an ion exchanger formed porously on the outer peripheral surface, the ion exchange rate can be increased while increasing the ion exchange capacity. 1 can be easily obtained.

Further, in the impregnation step S2 according to the present embodiment, the impregnating liquid is added to the fibers obtained in the papermaking step S1 to impregnate the fibers under vacuum or reduced pressure, so that the fiber layer 1a uniformly containing the ion exchanger can be obtained. it can. Furthermore, in the heating step S3 according to the present embodiment, the fiber layer (fiber body 2) containing the ion exchanger is heated at a predetermined temperature for a predetermined time to form the ion exchanger layer 1b on the outer peripheral surface of the fiber layer 1a. Since it is formed, an ion exchanger layer having a desired thickness dimension and porousness can be obtained by arbitrarily adjusting the heating temperature and heating time.

Although the present embodiment has been described above, the present invention is not limited to this, for example, the thickness dimensions of the fiber layer 1a and the ion exchanger layer 1b, the porosity of the fiber layer 1a, and the ion exchanger of the ion exchanger layer 1b. The filling rate and the like may be variously changed, and the method for forming the fiber layer 1a, the method for forming the ion exchanger, and the like may be used as other methods. Further, the fiber layer 1a may be a stack of a plurality of other fiber layers having different characteristics such as porosity, and the ion exchanger layer 1b is an ion exchanger in addition to the ion exchanger contained in the fiber layer 1a. It may contain an ion exchanger different from that of the exchanger.

An ion exchanger sheet having a fiber layer made of sheet-like fibers containing an ion exchanger and an ion exchanger layer made of an ion exchanger formed on the outer peripheral surface of the fiber layer and formed porously, and an ion exchanger sheet thereof. If it is a manufacturing method, it can be applied to those obtained by other configurations and manufacturing methods.

1 Ion exchanger sheet 1a Fiber layer 1b Ion exchanger layer 2 Fiber body 2a High concentration layer 2b High concentration layer 3 Teflon sheet 4 Teflon sheet S1 Manufacturing process S2 Impregnation process S3 Heating process S4 Processing process

Claims (10)

An ion exchanger sheet having an ion exchanger capable of removing impurity ions.
A fiber layer made of sheet-like fibers containing the ion exchanger and
An ion exchanger layer composed of the ion exchanger formed on the outer peripheral surface of the fiber layer and formed porously,
An ion exchanger sheet characterized by having. The ion exchanger sheet according to claim 1, wherein the ion exchanger layer is formed on either the front surface or the back surface of the fiber layer. The claim is characterized in that the fiber layer has a thickness dimension of 0.05 mm or more and 0.3 mm or less, and the ion exchanger layer has a thickness dimension of 0.01 mm or more and 0.1 mm or less. The ion exchanger sheet according to claim 1 or 2. The ion exchanger sheet according to any one of claims 1 to 3, wherein the ion exchanger layer has a thickness dimension of 0.1 or more and 0.5 or less of the total thickness dimension. .. The ion exchanger sheet according to any one of claims 1 to 4, wherein the ion exchanger is formed by being fixed to the fibers of the fiber layer with an organic binder or an inorganic binder. The ion exchanger sheet according to any one of claims 1 to 5, wherein the fibers constituting the fiber layer are made of hydrophilic fibers. The ion exchanger sheet according to any one of claims 1 to 6, wherein the ion exchanger is made of an inorganic powder. A method for producing an ion exchanger sheet having an ion exchanger capable of removing impurity ions.
The papermaking process of forming sheet-like fibers by papermaking,
An impregnation step of forming a fiber layer containing the ion exchanger by impregnating a sheet-shaped fiber obtained in the fabrication step with an impregnating solution containing the ion exchanger.
A heating step of forming an ion exchanger layer composed of the ion exchanger formed porously on the outer peripheral surface of the fiber layer by heating and drying the fiber layer obtained in the impregnation step.
A method for producing an ion exchanger sheet, which comprises. The method for producing an ion exchanger sheet according to claim 8, wherein the impregnation step is a vacuum impregnation or a vacuum impregnation impregnation by adding the impregnation liquid to the fibers obtained in the papermaking step. 8. The heating step is characterized in that the ion exchanger layer is formed on the outer peripheral surface of the fiber layer by heating the fiber layer containing the ion exchanger at a predetermined temperature for a predetermined time. Item 9. The method for producing an ion exchanger sheet according to Item 9.

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