JPH0640966B2 - Ion exchange fiber sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ion-exchange fiber sheet material capable of highly refining chemicals, liquids such as water and air, and gases.

[Conventional technology]

In recent years, the electronics-related industry, the field of fine chemicals such as medical fields, and the field of biological science have made remarkable progress, but along with this, the chemicals and water used in the manufacturing and distribution processes of these industries are also highly expensive. Purification, especially high-level cleaning with fine particles removed, is required. Furthermore, in these industries, high-level cleaning is indispensable even in the working environment, and high-level cleaning of indoor air is also required.

In order to meet these demands, the precision filtration method using a membrane filter or hepa filter has been conventionally used, but this method physically collects fine particles due to the pore size of the filter surface, resulting in excessive resistance. It is necessary to apply a large and large external pressure and to provide a large over-area, and there is a problem in operation that the life of the filter is short due to clogging of the surface of the body. In addition to the above, there is a fatal defect that a large amount of fine particles leak due to the performance of removing fine particles and that even fine particles that are an order of magnitude larger than the pore size of the filter leak.

Furthermore, technological advances such as miniaturization of product size and higher performance are intense in the above industry, and there is a limit in the conventional technology for cleaning chemicals, water, air, etc. corresponding to this, and in this direction in the future There is an increasing demand for improvements in the.

[Problems to be solved by the invention]

INDUSTRIAL APPLICABILITY The present invention provides a sheet-like material which has a low over-resistance, can be processed at a high flow rate, and has a long particle-removing life, which has excellent particle-removing performance and can supply extremely clean chemicals, water, and air. To do.

[Means for solving problems]

The present invention has the following constitution (1): Ion-exchange fiber flocs and glass fibers are mixed and dispersed, and the ion-exchange fibers have an island component mainly composed of a sea component having an ion exchange ability and a reinforcing polymer. An ion-exchange fiber sheet-like article, which has a sea-island structure consisting of and is at least partially branched or divided.

Hereinafter, the present invention will be described in detail.

It is essential that the ion-exchange fiber sheet material of the present invention is composed of ion-exchange fiber flock bodies and glass fibers. That is, the glass fiber mixed in the ion-exchange fiber flock body causes entanglement between the ion-exchange fiber flock body and excellent fibers, and maintains a dense surface fiber and an appropriate three-dimensional structure even after the sheet-like material is formed. The physical and chemical properties of glass fiber, such as its rigidity and chemical resistance, effectively act on the sheet form.

By adopting such a technical constitution, the ion-exchange fiber sheet material of the present invention can stably pass at a low pressure loss, and further, as described later, the three-dimensional shape of the ion-exchange fiber flock body achieved by a special technique. By acting synergistically with the structure, the adsorption performance of fine particles is high, and the filter life is dramatically extended.

Moreover, since the ion-exchange fiber sheet material of the present invention has an effect of easily removing the chemicals, water, and even ultrafine particles bearing ions in the air, its accuracy is in the order of one digit as compared with the prior art. It will improve.

The ion exchange fiber flock body constituting the present invention is
Although both the negative ion exchangers are docked electrostatically coupled bodies, it is essential that at least one of the ion exchangers is composed of ion exchange fibers. In other words, the fiber has a large surface area, the surface activity is correspondingly large, and the performance such as flexibility and physical strength are excellent.
It is considered that it effectively acts on the formation of flocs and the entanglement with glass fibers, and contributes to the appearance of excellent overperformance.

The ion-exchange fiber constituting the present invention is a core-sheath fiber composed of a sea component and an island component, and among them, a multi-core fiber is preferably applied. Such fibers include multi-core type composite fibers and multi-core type mixed fibers, but the multi-core type composite fibers are particularly preferable from the viewpoint of mechanical strength of fibers, physical properties of fibrils, and handleability.

The sea component constituting the fiber of the present invention includes polystyrene-based, polyvinyl alcohol-based, polyacrylic-based, polyamide-based, polyphenol-based, cellulose-based, and other known ion-exchange polymers having an ion-exchange group, but particularly Among poly (monovinyl aromatic compound) polymers, polystyrene polymers are most preferable because they have excellent chemical stability. Examples of such polystyrene-based polymers include homopolymers of styrene or α-methylstyrene, vinyltoluene, vinylxylene, chloromethylstyrene, etc., copolymers of two or more kinds of these or copolymers with other inert monomers, and polymers thereof (copolymers). Blends of are preferably used.

The characteristic of the sea component is that it has an ion exchange performance, and such performance is brought about by introducing a cation exchange group, an anion exchange group, a chelate group capable of forming a chelate, or the like.

Examples of such a cation exchange group include a strong acid cation exchange group having a sulfonic acid group, a medium acid cation exchange group having a phosphonic acid group, and a weak cation exchange group having a carboxylic acid group.

Examples of the anion exchange group include a strongly basic anion exchange group having a quaternary ammonium salt group and a weakly basic anion exchange group having a primary to tertiary amino group. As the chelate group, an iminodiacetic acid group, an aminocarboxylic acid group such as an iminodipropionic acid group, an amidoxime group, an aminophosphoric acid group,
Examples thereof include a polyamine group, a pyridine group and a dithiocarbamic acid group. Such an ion exchange group is at least 0.1 meq / g or more, preferably 0.
5 meq / g or more, particularly preferably 1.0 meq / g or more 10 meq / g
It is preferable that the content is within the range of g or less, and if the content is small, it is not preferable from the viewpoint of performance, while it is difficult and unrealistic to introduce the amount exceeding 10 meq / g.

It should be noted that the sea component polymer containing such an ion exchange group is extremely easily dissolved in a solvent such as water, and is usually insoluble even if it contains such an exchange group such as cellulose and is insoluble. It is insolubilized to such an extent that it is at least insoluble in water.

The degree of such crosslinking can be roughly determined by the water content. The water content varies depending on the amount of ion-exchange groups, but is mainly determined by the degree of crosslinking. The preferred water content in the fiber of the present invention is 0.5 or more.

Here, the water content means that the Na-type (Cl-type) cation (anion) exchange fiber is immersed in distilled water, and then centrifugally dehydrated for 5 minutes with a household centrifugal dehydrator to remove surface moisture, and immediately the weight ( It is a value obtained by measuring W), further drying, and weighing (W ₀ ).

Moisture content = W−W ₀ / W ₀ The island component of the fibers constituting the present invention is a reinforcing polymer, and specific examples thereof include homopolymers such as polyester, polyamide, and poly α-olefin, or copolymers thereof, or These blends are used, and polyα-olefins are most preferable because they have excellent chemical resistance. Examples of such poly α-olefins include polypropylene, polyethylene, poly-3-methylbutene-1, poly-4-methylpentene-1, and the like, and blends thereof.

Among such sea-island components, the blending ratio ((B) / (A) + (B)) of the polystyrene-based polymer (A) and the poly α-olefin-based polymer (B) as the sea-component is 50% by weight or less, particularly The combination of 3 to 40% by weight of the blend and the poly-α-olefin polymer (B) as the island component is particularly advantageous in the present invention in terms of peel resistance, chemical resistance, yarn-forming property and fiber physical property. Suitable for the fibers of

The ratio of the island component of the fibers constituting the present invention is 10 to 90% by weight, preferably 20 to 80% by weight, and particularly preferably 70% by weight or less. If this ratio is too low, the mechanical strength will be low, and conversely, if it is too high, the ion exchange performance will be adversely affected, which is not preferable.

The number of islands in the fiber is not particularly limited, but is preferably 5 or more and 300 or less. If the number of islands is too small, it is difficult to form fibrils and the thickness of the fibrils becomes too thick. On the other hand, if the number of islands becomes too large, the fibrils become thin and weak, which is not preferable.

The single yarn fineness of such fibers is about 0.1 to 500 d, but 1 to 50 d is particularly preferable from the viewpoint of mechanical properties and practicality. The fiber cross section is preferably circular or non-circular because it has a large surface area. The fiber of the present invention has a fiber length of 0.1 to 200 mm along the fiber axis, preferably 0.2 to
The shape of the cut fiber cut to 50 mm is good, and it is selected according to the kind of the intended product.

When the floc body of the present invention is formed, the mixing composition ratio ((C) / (D)) of the ion exchange fiber (C) and the ion exchanger (D) having the opposite charge is 1/10 based on the dry weight.
It is good to be in the range from 10/1. That is, if it is outside the above range, it tends to be difficult to form a flock body,
Particularly preferably, a range of 1.5 / 10 to 10 / 1.5 provides a flock body having excellent floc-forming ability and adsorption ability.

The opposite charge ion exchanger constituting the present invention means an insoluble ion exchanger having an ion exchange group. Specific examples thereof include natural products such as cellulose, sephadex and polysaccharides such as agarose, and polystyrene-based, polyphenol-based polyvinyl alcohol-based, polyacrylic-based, polyamide-based and other synthetic organic polymers (ion-exchange polymers). A known organic ion exchanger having an exchange group introduced therein can be mentioned. Examples of the shape of the ion exchanger include powders, granules, fibers and membranes. Among them, fibers and powders, especially fibers are preferable because they are easy to handle and have excellent adsorption ability.
As such a powder, a powder having an average particle diameter of 300 μm or less, and further a powder having a small average particle diameter of 200 μm or less is easier to form flocs and is preferable in the present invention. Further, as the ion exchange fiber, it is preferable to use a fiber made of a fiber for ion exchange and a polymer for reinforcement as a base material because it has sufficient mechanical strength in operation and shape retention.

The ion-exchange fiber floc constituting the present invention is an ion-exchange fiber and both components of the ion-exchanger having an opposite electric charge are uniformly dispersed in water or a water-soluble solvent, and both suspensions are stirred. Obtained by mixing.

In short, the floc body of the present invention is formed as long as the system allows ions to act as ions, and it is not necessary to limit it to a specific solvent. Such ions are used because the ions are usually active in water or water-soluble solvents.
The water-soluble solvent is a solvent having a property of dissolving in water, and for example, alcohols such as methyl alcohol and ethyl alcohol are mainly used.

The floc body formed in such a solvent is obtained in a state of being suspended in the above mixed liquid.

As the ion exchanger of the present invention, for example, a cation exchanger having a sulfonic acid group, a phosphonic acid group, a carboxylic acid group or the like introduced therein, or, for example, an anion exchanger having a primary to tertiary amino group or a quaternary ammonium group introduced thereinto. Further, it is an ion exchanger into which various chelate groups such as an aminocarboxylic acid group, an amidoxime group, a polyamine group, an aminophosphoric acid group and a dithiocarbamine group are introduced.

In particular, a sulfonic acid group is preferably used as the cation-exchange group and a quaternary ammonium group is preferably used as the anion-exchange group for the effect.

A feature of the ion exchange fibers of the present invention is that they are at least partially branched or split, the branching or splitting being primarily based on the destruction of marine components, in mixers in solvents such as water. It is achieved by mechanically treating with a stirrer.

The mixer can use the apparatus normally used. Mixing time with a mixer is usually 1,000 to 10,000 rpm
m, 0.1-20 minutes, preferably 1-5 minutes. The mixing time and the rotation number are related to the degree of fiber division or branching, and are selected according to the actual situation.

By adopting such a constitution, the entanglement between the fibers is increased, and a sheet-like material having a sheet forming ability, particularly an affinity with glass fibers, can be obtained.

Glass fiber constituting the present invention, soda lime glass,
It is a known glass such as potassium lime glass, lead glass, and quartz glass, and the fiber diameter is preferably 0.01 to 500 μm, more preferably 0.1 to 50 μm in terms of physical strength and practicality. The cross section of the fiber may be circular or non-circular, and the fiber length is 0.1 to 100 mm, preferably 0.2 to 50 mm for forming the sheet-like material, but it is selected according to the kind of the intended product. Usually, commercially available pulp-like glass fibers within the above range are preferably used.

The mixing ratio of the glass fibers constituting the present invention is 99/1 to 20/80, preferably 98/2 to 30/70 (dry weight basis) of ion exchange fiber flock / glass fiber. If it is out of this range, the effect of improving liquid permeability, filter life, etc. becomes small, and the performance of removing fine particles deteriorates, which is not preferable.

The glass fibers may be mixed by adding the glass fibers to the mixed liquid in which the ion-exchange fiber flocs float, or by mixing in the step of partially branching or dividing the ion-exchange fibers. You may. Further, a method of collectively carrying out these steps, that is, an ion exchange fiber, an ion exchanger having an opposite charge, and a glass fiber may be stirred and mixed in water or a water-soluble solvent.

The mixed suspension is sucked under suction to obtain a sheet, and if necessary, pressed under pressure or dried to obtain a sheet comprising the ion-exchange fiber flocs and glass fibers of the present invention. To be

The basis weight of the ion-exchange fiber sheet material of the present invention is not particularly limited, but generally 100 to 2000 g / m ² is used depending on the application.

The ion-exchange fiber sheet material of the present invention can be achieved by mixing or combining with other inert fibers (normal organic and inorganic fibers). As such an inert fiber,
Although various fibers can be applied, polyolefin fibers, aramid fibers, carbon fibers, alumina fibers and the like are preferable from the viewpoint of chemical resistance, and the mixing ratio is 5 to 80% by weight based on the dry weight of the ion exchange fiber sheet material. Is suitable for increasing the strength of the sheet.

The ion-exchange fiber sheet material of the present invention is used for the purification of inorganic chemicals and organic chemicals, especially methanol, ethanol, iso-propyl alcohol, dimethyl sulfoxide, acetic acid, etc., and hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, ammonia. Used in the purification and cleaning of liquids such as water, hydrophilic chemicals such as hydrogen chloride and gases such as ammonia, and the purification and cleaning of water and air.

It is also used in the fine polymer manufacturing process and the food manufacturing process in the textile industry.

In addition, it is used as a collection / separation sheet for dilute ions and colloidal substances in solutions, or as an analysis paper, and also as an air filter for capturing dust in the air, proteins such as enzymes, cells such as viruses and cells, microorganisms, etc. Used for filters, etc.

Furthermore, it is used as a pre-coat material for condensate water purification in nuclear power plants and general boilers, as well as for purifying contaminated water.

Furthermore, in recent years, water quality such as odor and coloring, especially water quality deterioration of drinking water has become a social problem, but the ion-exchange fiber sheet material of the present invention has an excellent effect of deodorization and decolorization, and water quality particularly drinking water quality. Used for improvement.

Further, the ion-exchange fiber sheet material of the present invention is activated carbon,
It may be used in combination with bone charcoal, activated carbon fiber or a sheet-shaped material (filter) thereof.

The composite of the above-mentioned ion exchanger and activated carbon, bone charcoal, activated carbon fiber, or a mixed sheet is preferably used as a water quality improver.

〔The invention's effect〕

The features of the present invention are, firstly, that the overresistance is small, the fluid can be processed at a high flow rate, and the filter life is long.
In particular, it has an excellent effect on overperformance of highly viscous fluids and high-temperature fluids, and secondly, it has an excellent performance of removing fine particles, and is particularly effective for ultrafine particles of about 0.1 μm, which were difficult to remove by the conventional method. is there.

〔Example〕

 The present invention is described in detail below with reference to examples.

Example 1 Polystyrene (manufactured by Asahi Dow, Styron # 679) 40
And polypropylene (Mitsui Toatsu, Noblen J3H
-G) Using 10 parts of the blended product as a sea component and 50 parts of polypropylene (same product) as an island component, and spinning temperature of 270 ° C.
Was melt-spun with a sea-island type composite spinneret (the number of islands was 16), and was wound after being treated with an oil agent at a spinning speed of 1000 m / min. The obtained 420 denier, 42 filament multifilament was cut into a fiber length of 1.0 mm along the fiber axis direction,
The cut fiber obtained is divided into two parts, one of which is sulfuric acid 2
After soaking in a cross-linking solution of 2 parts, 104 parts of nitrobenzene and 0.3 parts of paraformaldehyde for 6 hours at room temperature,
After washing and drying with distilled water and methanol, soak in sulfuric acid at 90 ℃
Was reacted for 2 hours to sulfonate, and the other was immersed in a cross-linking solution consisting of 5 parts of paraformaldehyde, 25 parts of acetic acid and 70 parts of concentrated sulfuric acid to carry out a cross-linking reaction at 80 ° C. for 2 hours to insolubilize polystyrene as a sea component. Next, the crosslinked yarn was immersed in a solution consisting of 85 parts of chloromethyl ether and 15 parts of stannic chloride and reacted at 30 ° C. for 1 hour. 10 after completion of reaction
% Hydrochloric acid, distilled water, and acetone, and soak this chloromethylated thread in 30% trimethylamine aqueous solution at 30 ° C.
A cross-linking group and an ion-exchange group were introduced into the polystyrene part by amination for 1 hour. The type of exchange group is a strong acid cation exchange fiber having a sulfonic acid group, an exchange capacity of 2.8 meq / g-Na, and a water content of 1.5, and the latter is a strong base having a quaternary ammonium group. Anion exchange fiber, exchange capacity 2.3 meq /
It was g-Cl and the water content was 2.3.

Ion-exchanged water 6 was added to 100 g (dry weight) of the obtained cation-exchange fiber, and the ion-exchange fiber was sufficiently dispersed while stirring at 100 rpm.

Separately, ion-exchanged water 6 was added to 100 g (dry weight) of anion-exchange fiber, the ion-exchange fiber was sufficiently dispersed while stirring at 100 rpm, and this was gradually added to the liquid in which the cation-exchange fiber was dispersed. And 100 rpm
After continuously stirring for 30 minutes, the flocs were taken out and dehydrated.

A mixture of the thus-obtained ion-exchange fiber flock body (E) and glass fiber (GB-100R of Toyo Paper) (F) in various ratios ((E) / (F) = 100/0 to 0/10).
0), 400 parts of water was added to 1 part (dry weight) of the mixture, and mixed with a mixer (VA-835, manufactured by Hitachi) at 7000 rpm for 3 minutes. Then, add this to 15 aquarium and mix it by hand to add 25
It was sucked through a 400-mesh wire mesh having a square size of 25 cm to obtain a sheet-like material having a basis weight of 100 g / m ² (dry basis). This was pressed at a pressure of 10 kg / cm ² for 3 minutes and then dried at 60 ° C. for 1 minute to obtain an ion exchange fiber sheet.

Isopropyl alcohol was passed under reduced pressure using the sheet material. The amount of permeated liquid per unit area and the removal rate of fine particles are shown in Table 1.

The ion-exchange fiber sheet material of the present invention has good liquid permeability,
Moreover, the liquid permeability does not decrease even after 10 hours,
It was shown that it is an excellent sheet-like material having a high particulate removal effect and a long filter life.

Example 2 and Comparative Example 1 6 parts of the cation exchange fiber obtained in Example 1 and an anion exchanger (powder having an average particle size of 100 μm, Powdex PAO OH)
Form) An ion-exchange fiber floc body consisting of 1 part was prepared. 90 parts of the ion exchange fiber flock body and glass fiber 1
After 0 part of the mixture was treated with mixer in water by the method of Example 1, an ion exchange fiber sheet having a basis weight of 100 g / m ² was obtained (Example 2).

In addition, a commercially available membrane filter (pore size 0.2
It was set as the comparative example 1 using (micrometer). DMSO was filtered through these two filters. The over-resistance value and the effect of DMSO for removing fine particles are shown in Table 2. It was shown that the sheet-like product of the present invention has extremely low overresistance and a high particulate removal rate.

Example 3, Comparative Example 2 Ion-exchange fiber sheet material obtained in Example 2 (Example 3)
10% of the sheet (Comparative Example 2) obtained in the same manner as in Example 2 except that 10 parts of glass fiber was not added to the sheet-like product of Example 2 but 10 parts of polyethylene pulp (manufactured by Mitsui Petrochemical Industry Co., Ltd.) was added. Concentration of hydrochloric acid was carried out at normal pressure.
Liquid permeability and fine particle removal rate are shown in Table 3.

The ion-exchange fiber sheet material of the present invention showed excellent overperformance.

Claims (1)

[Claims] 1. A sea-island structure comprising ion-exchange fiber flocs and glass fibers mixed and dispersed, wherein the ion-exchange fibers are composed of a sea component having ion-exchange ability and an island component containing a reinforcing polymer as a main component. And at least partially
An ion exchange fibrous sheet, which is branched or divided.