JP2019063757A - Manufacturing method of hollow fiber membrane-like adsorbent - Google Patents

Abstract

To provide a method for manufacturing a hollow fiber membrane-like adsorbent mainly containing a fine powdery adsorbent, fixed at a state that the fine powdery adsorbent and reaction efficiency close to time of powder single use is maintained, and excellent in pressure resistance and flexibility.SOLUTION: A manufacturing method of a hollow fiber membrane-like adsorbent includes a spinning process for discharging a spinning slurry from a slurry discharge port by using a dry wet type spinning device and discharging a core liquid from a core liquid discharge port and injecting the same to a coagulation bath to obtain a hollow fiber membrane-like adsorbent, in which the hollow fiber membrane-like adsorbent contains a fine powdery adsorbent and an organic polymer binder, has percentage content of the fine powdery adsorbent in a range of 70 wt.% to 80 wt.%, membrane thickness in a range of 0.3 mm to 1.3 mm, and a slit structure in a diameter direction in an inner side, the spinning slurry is manufactured by dissolving the organic polymer binder in a solvent and dispersing the fine powdery adsorbent, and has viscosity of 1.0 Pa s to 6.5 Pa s, and dissolved residue amount of gas is saturated amount or more at a slurry discharge temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a hollow fiber membrane-like adsorbent.

  Hollow fiber membranes are generally organic polymer membranes, and microfiltration membranes (MF (Microfiltration) membranes), ultrafiltration membranes (UF (Ultrafiltration) membranes), nanofiltration membranes (NF) depending on the pore size and use There are various types such as (Nanofiltration) membrane, reverse osmosis membrane (RO (Reverse Osmosis) membrane), etc. Hollow fiber membranes of these organic polymers are usually bundled in plural to make a cartridge module and used for clean water application Be done.

  Organic polymer filters are also used for air freshening applications. As this organic polymer filter, there is known a product in which an inorganic photocatalyst such as titanium dioxide or zeolite or an inorganic adsorbent is compounded in order to impart a specific harmful substance removing function. For example, products using an organic polymer filter containing zeolite as a main component in the air as a deodorizing agent or an exhaust gas filter are known.

  These organic polymer filters are manufactured, for example, by kneading zeolite or the like with an organic polymer as a binder, or spraying zeolite or the like onto the organic polymer filter. Patent Document 1 discloses an air purifying filter provided with a deodorizing filter medium carrying a deodorizing enzyme. This deodorizing filter medium is a method such as coating, impregnating, kneading into raw materials, or the like, an inorganic adsorptive deodorizing agent such as zeolite together with a deodorizing enzyme into a base material such as a nonwoven fabric or woven fabric using synthetic fibers. It is manufactured to carry.

  Another supporting method is a technique of impregnating a non-woven fabric of an organic polymer or the like with a raw material of zeolite to crystallize the zeolite to fix the zeolite. Patent Document 2 discloses a woven fabric having fibers made of an inorganic porous crystal-hydrophilic polymer composite. The inorganic porous crystal-hydrophilic polymer composite (zeolite-supporting pulp) is prepared by impregnating the pulp with an aqueous solution of sodium metasilicate / 9-hydrate, adding a mixed aqueous solution of sodium aluminate and sodium hydroxide, 90 ° C. It is manufactured by the method of immersing with.

  Patent Document 3 discloses a hygienic tissue paper containing metal ion-containing cellulose fibers containing ions of metal elements, and relates to the technology of Patent Document 2 described above, wherein the zeolite is physically supported in the cellulose fibers It has been pointed out that, because of this, there is a problem that the zeolite is easily detached, and there is a problem that the fiber is deformed, damaged and shortened due to the reaction when supporting the zeolite or the like on the cellulose fiber.

  Moreover, the present inventors disclose a natural zeolite hollow fiber porous body in Patent Document 4. The natural zeolite hollow fiber porous body is composed of natural zeolite powder and 3 to 50% by weight of an organic polymer, and is obtained by wet spinning using an organic polymer as a binder and liquid phase separation. This natural zeolite hollow fiber porous body is a multi-purpose porous body in which pores with a plurality of diameters are distributed in the range of 0.01 to 100 microns in pore diameter, and the organic polymer holds the grain boundary of the adsorbent. It has water resistance that can be flooded, and the properties of the original natural zeolite are maintained.

JP, 2004-041276, A Patent No. 4149066 International Publication No. 2016/031749 JP 2012-72534 A

  In the technique described in Patent Document 1, it is difficult to firmly fix a large amount of deodorizing enzymes and inorganic adsorptive deodorizing agents on a substrate.

  Moreover, in addition to the problem which patent document 3 shows, the technique of patent document 2 has the problem that application is difficult depending on the kind of zeolite. For example, since MFI-type zeolite must be synthesized for a long time under high alkali conditions under high alkali conditions, when applied to the technology described in Patent Document 2, the strength of the organic polymer fiber as a carrier may be reduced or decomposed. It is thought that.

  In addition, the techniques described in Patent Document 1 and Patent Document 2 are assumed to be used in a gas phase system such as an air cleaning application. Most of the inorganic adsorbents such as zeolites used for these are fine particles of nano to micron size or less, and are highly hydrophilic. As a result, when the inorganic adsorbent is used not in a gas phase but in a liquid phase, it disperses in solution with crystal particle size, and it is difficult to completely separate it even using a filter.

  Therefore, when using a particulate inorganic adsorbent in a liquid phase system, for example, it may be solidified together with a sinterable clay mineral, titanium oxide, etc. and used as a sintered body such as pellets. However, when the inorganic adsorbent is a pellet-type sintered body, the performance as the adsorbent is often lower than that of the original adsorbent. In addition, when the specific surface area is increased to increase the reactivity of the pellet-type sintered body, the pressure resistance and the water resistance become low, and in many cases, they are easily broken. Furthermore, if the pellet-type sintered body is compacted densely to increase the physical strength, only the outer surface can be used for the reaction, and the reactivity may be lowered. Thus, it is difficult for the pellet-type sintered body to have both reactivity, pressure resistance, water resistance, and physical strength.

  Although the natural zeolite hollow fiber porous body described in Patent Document 4 solves the problems of the pellet-type sintered body of the fine powdery adsorbent as described above, it is further required to increase the filtration processing amount. It has become to.

  As a method of raising the amount of filtration processing of the natural zeolite hollow fiber porous body which is described in patent document 4, the method of raising the content rate of fine powdery adsorbent can be considered. In addition, the porosity of the hollow fiber porous body can be increased, the film thickness of the hollow fiber porous body can be reduced, or the pressure resistance of the hollow fiber porous body can be increased to increase the fluid pressure, and the filtrate can be formed inside There is a way to increase the diffusion effect of Further, as a method of increasing the amount of filtration processing in the case of a normal organic polymer membrane, a method of bundling a large number of hollow fibers having a small outer diameter and a thin film thickness to form a module and increasing the wetted area can be considered.

  Regarding the method of increasing the content of the fine powder adsorbent, when the content of the fine powder adsorbent is as high as about 50% by weight, the bonds between the organic polymers are weakened by the dispersion of the fine powder adsorbent, usually There is a problem that it is difficult to obtain strength as in the case of a film made of only the organic polymer of the above, and sufficient pressure resistance can not be obtained. Further, as in the case of a normal organic polymer film, there is a problem that sufficient pressure resistance can not be obtained if the outer diameter of the hollow fiber is thin and the film thickness is thin in order to modularize and increase the liquid contact area.

  Furthermore, when the content of the fine powdery adsorbent is as high as about 50% by weight, if the outer diameter is made smaller or the film thickness is made thinner, the hollow fiber is broken by the internal pressure supply when the supply liquid has a high viscosity. External pressure supply has a problem that the hollow fiber is crushed and the filtration efficiency is reduced.

  As described above, when the content of the fine powder adsorbent in the hollow fiber membrane is increased to enhance the removal / extraction effect by the fine powder adsorbent, the content of the organic polymer functioning as a binder decreases, There is a problem that sufficient pressure resistance can not be obtained, and the use under pressured conditions becomes difficult.

  Therefore, the problem of the present invention is that the main component is a fine powdery adsorbent, and the fine powdery adsorbent is stably immobilized in a state in which the reaction efficiency is maintained close to that at the time of using the powder alone, It is an object of the present invention to provide a method for producing a hollow fiber membrane-like adsorbent excellent in flexibility.

  The present inventors diligently studied to achieve the above object. And in order to improve pressure resistance and the amount of filtration processing without reducing the content rate of the adsorbent for the hollow fiber membrane adsorbent, the film thickness of the hollow fiber membrane is increased to about 1 mm, and the slit structure is further inside. A hollow fiber membrane-like adsorbent was formed by intentionally forming a large amount of. And, it has been found that such a structure can reduce the resistance due to the immersion liquid while maintaining the filtration processing amount and increasing the separation efficiency.

  In addition, considering the method of manufacturing such hollow fiber membrane adsorbing material, degassing of the slurry for spinning generally performed to suppress defect formation at the time of hollow fiber membrane formation not only hinders formation of the slit structure. , It was found to bring about a decrease in elongation at break. And in order to prevent them, it discovered that it was important to prepare the slurry for spinning which kept the amount of gas dissolved high.

  Furthermore, the hollow fiber membrane-like adsorbent having a large number of slit structures on the inside, which is spun using such a slurry for spinning, has flexibility to reduce damage to the membrane module by molding and repeated use. Found out.

  In addition, under the spinning conditions in the dry-wet spinning method, the slit structure inside the hollow fiber is formed at the two-liquid interface between the core liquid and the spinning slurry. Therefore, in the technique of Patent Document 4, the slit structure is created only when the mixing amount of the organic polymer binder in the spinning slurry is about 33% or more of that of the molded body. However, when the preparation conditions of the slurry for spinning and the viscosity are controlled, the content of the fine powdery adsorbent is increased, and the content of the organic polymer binder is reduced to about 20% of the molded body, It was found that a slit structure was created.

  The present inventors have completed the present invention based on these findings.

  That is, the present invention includes the following aspects.

A method for producing a hollow fiber membrane adsorbent, which comprises
The hollow fiber membrane adsorbent comprises a fine powder adsorbent and an organic polymer binder,
The content of the fine powdery adsorbent is in the range of 70% by weight to 80% by weight,
The content of the organic polymer binder is in the range of 20% by weight to 30% by weight,
The film thickness is in the range of 0.3 mm to 1.3 mm,
Has a radial slit structure inside,
The spinning slurry is discharged from the slurry discharge port using a dry-wet spinning apparatus provided with a double-opening nozzle having a core liquid discharge port and a slurry discharge port located on the outer periphery thereof, and from the core liquid discharge port The core solution is discharged, and the coagulation bath solution is provided with a free running distance and injected to obtain a hollow fiber membrane-like adsorbent;
In the slurry for spinning, the organic polymer binder is dissolved in a solvent, the finely powdered adsorbent is dispersed, and the viscosity is 1.0 Pa.s. s or more 6.5 Pa. The manufacturing method of the hollow fiber membrane-like adsorbent whose s or less and the dissolved amount of gas are more than the saturation amount in slurry discharge temperature.

  It is preferable that the amount of dissolved gas at the time of discharge of the slurry for spinning is larger than the amount of saturation at the slurry discharge temperature.

The spinning slurry is
The temperature of the mixed solution containing the organic polymer binder and the solvent, the temperature is lower than the slurry discharge temperature, and the gas is dissolved, and the temperature is raised while stirring to the slurry discharge temperature. A binder solution preparing step of dissolving a binder in a solvent and obtaining a binder solution in which the ratio of the amount of dissolved gas to the amount of gas saturation is increased;
It is preferable that the fine powdery adsorbent be obtained by a slurry preparation step in which the fine powdery adsorbent is added in plural times so as to suppress the foaming of the liquid surface while stirring the binder solution.

  It is preferable to further include a gas dissolving step of dissolving a gas in the solvent before the binder solution preparing step.

  In the spinning step, the temperature at which the spinning slurry and the core liquid are discharged causes dissolution of the dissolved air from the slurry to facilitate diffusion of the core liquid during phase separation which occurs when the spinning slurry contacts the core liquid. It is preferable that the temperature is such that a macro slit-like structure is formed inside the hollow fiber membrane adsorbent.

  The organic polymer binder is preferably a polyethylene polyvinyl alcohol copolymer resin or polyether sulfone, and the fine powder adsorbent is preferably a fine zeolite powder.

The discharge temperature of the slurry is in the range of 20 ° C. to 80 ° C.,
The core liquid is water or an aqueous solution having a discharge temperature in the range of 20 ° C. to 40 ° C.,
The coagulation bath liquid is preferably water or an aqueous solution having a temperature in the range of 20 ° C to 50 ° C.

  The breaking elongation of the hollow fiber membrane adsorbent is preferably 10% or more.

  According to the present invention, the main component is a fine powdery adsorbent, and the fine powdery adsorbent is stably immobilized in a state in which the reaction efficiency is maintained close to that at the time of using the powder alone, and pressure resistance and flexibility A method of producing a hollow fiber membrane-like adsorbent excellent in

Cross-sectional SEM image of the hollow fiber membrane-like adsorbent of Example 1 High-magnification SEM image of Figure 1 Photograph of a membrane module obtained by bundling the hollow fiber membrane adsorbent of Example 1 Cross-sectional SEM image of the hollow fiber membrane-like adsorbent of Comparative Example 2

  Next, a preferred embodiment of the present invention will be described. In the present invention, the description of the numerical range includes not only both end values but all arbitrary intermediate values included therein.

The present invention is a method for producing a hollow fiber membrane-like adsorbent. The hollow fiber membrane-like adsorbent according to the present invention contains a fine powder adsorbent and an organic polymer binder, and the content of the fine powder adsorbent is in the range of 70% by weight to 80% by weight, and the organic polymer The binder content is in the range of 20% by weight to 30% by weight. The hollow fiber membrane-like adsorbent according to the present invention has a film thickness in the range of 0.3 mm to 1.3 mm, and has a slit structure in the radial direction on the inner side.
In addition, the manufacturing method of the present invention discharges the spinning slurry from the slurry discharge port using a dry-wet spinning apparatus provided with a double port nozzle having a core liquid discharge port and a slurry discharge port positioned on the outer periphery thereof. At the same time, the core liquid is discharged from the core liquid discharge port, and the coagulation bath liquid is provided with a free running distance and injected, and a spinning step for obtaining a hollow fiber membrane adsorbent is included.
Here, in the slurry for spinning, the organic polymer binder is dissolved in a solvent, the finely powdered adsorbent is dispersed, and the viscosity is 1.0 Pa.s. s or more 6.5 Pa. The amount of dissolved gas is equal to or more than the amount of saturation at the slurry discharge temperature.

  The hollow fiber membrane-like adsorbent obtained by the production method of the present invention is an adsorbent in the form of a hollow fiber membrane, which contains a fine powder adsorbent and an organic polymer binder. This hollow fiber membrane-like adsorbent is mainly composed of a fine powdery adsorbent, and is thicker than a general hollow fiber membrane for water purification (film thickness 50 μm to less than 300 μm), and its cross-sectional structure is an inner wall It is a multi-purpose porous body having a radial slit structure on the side.

(Fine powdery adsorbent)
The fine powdery adsorbent used in the present invention is not particularly limited as long as it is a solid powder particle capable of adsorbing a substance, and examples thereof include particles such as acid clay and natural or synthetic zeolite. Among them, natural or synthetic zeolite is preferable, and synthetic zeolite is more preferable.

  The particle size of the finely powdered adsorbent is not particularly limited, but is preferably 0.5 mm or less, more preferably submicron size to micron size, and still more preferably 0.1 μm to 5 μm. The particle size of the fine powdery adsorbent is, for example, analysis using a particle size distribution measuring apparatus such as laser diffraction scattering method, dynamic light scattering method, Coulter method, centrifugal sedimentation method, scanning electron microscope (SEM), etc. Ten arbitrary particles can be selected from the photomicrograph of and measured as their surface area average diameter. As a measuring method, the measurement by a SEM photograph is preferable. Here, the particle size is the average particle size of the agglomerated particles of the fine powdery adsorbent used in the preparation of the slurry, and the agglomerated particles are not separated due to the formation of agglomerates of particles having a grain size smaller than this range. including.

  The fine powdery adsorbent may be used singly or in combination of two or more kinds, but when it is a mixture of two or more kinds, one hollow fiber membrane adsorbent selectively adsorbs a plurality of kinds of substances simultaneously or The hollow fiber membrane-like adsorbent can be made multifunctional, such as being removable.

  The content of the finely powdered adsorbent of the hollow fiber membrane-like adsorbent according to the present invention is in the range of 70% by weight to 80% by weight. The hollow fiber membrane adsorbent of the present invention is higher in content of the fine powder adsorbent than the conventional hollow fiber membrane adsorbent, and the hollow fiber membrane adsorbent has particularly high adsorption performance.

(Organic polymer binder)
The organic polymer binder used in the present invention is not particularly limited as long as it has a function as a binder (binding agent) and can be formed by bonding fine particles of the fine powder adsorbent as described above, but the liquid described later It is preferable that the fine powdery adsorbent can be formed by the phase separation method. As such an organic polymer binder, polysulfone, polyether sulfone, polyether imide, polyamide imide, polyethylene polyvinyl alcohol copolymer resin etc. are mentioned.

  The organic polymer binder is preferably an organic polymer soluble in dimethyl sulfoxide, and examples of such an organic polymer binder include polyether sulfone and polyethylene polyvinyl alcohol copolymer resin. Among the polyethylene-polyvinyl alcohol copolymer resins, those having a molar ratio of ethylene monomer units of 44% or more are preferable. The hollow fiber membrane-like adsorbent made of polyethylene-polyvinyl alcohol copolymer resin is preferably stored at room temperature because when heated to 150 ° C. or higher, the resin hardens and the flexibility and reactivity decrease.

  The content rate of the organic polymer binder of the hollow fiber membrane-like adsorbent according to the present invention is in the range of 20% by weight to 30% by weight. When the content of the organic polymer binder is in this range, the hollow fiber membrane adsorbent is particularly excellent in mechanical stability and possibility of continuous use.

(Hollow fiber membrane adsorbent)
Hereinafter, the structure of the hollow fiber membrane-like adsorbent according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional SEM image of one embodiment of a hollow fiber membrane-like adsorbent according to the present invention, and FIG. 2 is a high-magnification cross-sectional SEM image of the same.

  The hollow fiber membrane-like adsorbent according to the present invention is in the form of a hollow fiber membrane. The thickness (film thickness) of the hollow fiber membrane is in the range of 0.3 mm to 1.3 mm. In FIG. 1, a hollow fiber membrane-like adsorbent having a thickness of about 0.9 mm is shown. The film thickness of the hollow fiber membrane for water purification generally marketed is 0.05 mm or more and less than 0.3 mm, and is thicker than this. The thickness (film thickness) of the hollow fiber membrane-like adsorbent according to the present invention is preferably 0.3 mm to 1.3 mm, and more preferably 0.5 mm to 0.9 mm. When the film thickness is in this range, the contact ratio between the substance to be adsorbed in the solution which permeates the membrane and the fine powdery adsorbent can be increased to enhance the adsorption effect. The outer diameter of the hollow fiber membrane-like adsorbent is not particularly limited, but is preferably 1.5 mm to 4 mm, and more preferably 2 mm to 3 mm. In FIG. 1, a hollow fiber membrane-like adsorbent having an outer diameter of about 3 mm is shown.

  The hollow fiber membrane-like adsorbent according to the present invention has a radial slit structure inside. As seen in FIG. 1, the slit structure is formed so that the slit structure is formed radially outward from the central axis of the hollow fiber. The width of the slit structure is about 0.1 mm to 0.01 mm, and the width of the slits on the outer peripheral side tends to be large. FIG. 1 shows a hollow fiber membrane-like adsorbent having a large number of large slit structures from the inside toward the outer peripheral direction. This slit structure enhances the flexibility of the hollow fiber membrane-like adsorbent. In addition, even when the content of the organic polymer binder is low, it is possible to obtain the pressure resistance and the flexibility of the film against the pressure supply. In addition, when the hollow fiber membrane adsorbent has a pleated slit structure inside, the area where the feed liquid contacts the fine powder adsorbent can be expanded when supplying the feed liquid, and the adsorption effect can be enhanced. . The slit structure is formed on the inner side of the hollow fiber membrane-like adsorbent, and a shallow slit formed in the coagulation bath is separately present on the outer periphery of the hollow fiber membrane-like adsorbent. The region in which the slit structure of the hollow fiber membrane adsorbent is formed is preferably 50% or more of the film thickness on the inner side, more preferably 60% or more, and 70% or more. It is particularly preferred that The structure forming the slit structure and the structure of the outer periphery without the slit structure affect the flexibility and strength of the hollow fiber membrane adsorbent.

  In FIG. 2, it is possible to observe a fine powdery adsorbent having a diameter of several μm and an organic polymer binder in which the fine powdery adsorbent is adhered and which forms a slit structure. The organic polymer binder is a carrier of the fine powder adsorbent, and appears on the surface of the structure in which a part of the surface of the fine powder adsorbent forms the organic polymer binder. In addition, the slit structure is continuous. Therefore, the slit structure also provides a path for transporting the adsorbed substance and the medium from the outside or the inside of the hollow fiber to the finely powdered adsorbent.

(Preparation of slurry)
In the present invention, first, a slurry in which a fine powdery adsorbent is dispersed is prepared in a solution in which an organic polymer binder is dissolved in a solvent, and the slurry is used to make hollow by the phase separation method in the spinning step described later. A yarn film adsorbent is formed. The slurry had a viscosity of 1.0 Pa.s. s or more 6.5 Pa. The s or less, and the dissolved amount of gas is more than the saturation amount in the slurry discharge temperature mentioned later are prepared.

  The viscosity of the slurry was 1.0 Pa.s. s or more 6.5 Pa. By setting the thickness to s or less, it becomes possible to form a thick hollow fiber membrane-like adsorbent, and by making the dissolved amount of the slurry gas more than the saturation amount at the slurry discharge temperature, it is possible to form a thick membrane. It is possible to form a large number of radial slit structures inside the hollow fiber membrane adsorbent.

  The solvent used in the present invention is not particularly limited as long as it can dissolve the organic polymer binder, but has a relatively high flash point and causes a chemical or physical reaction with the fine powder adsorbent or the organic polymer binder. However, it is preferable that they can be dissolved or uniformly dispersed, and that they do not easily remain in the hollow fiber membrane-like adsorbent which is a molded body. For example, although what is generally used as an organic solvent can be used, when using a polyethylene polyvinyl alcohol copolymer resin or polyether sulfone as an organic polymer binder, dimethyl sulfoxide or normal methyl pyrrolidone is preferable.

  The order of mixing the solvent, the fine powdery adsorbent and the organic polymer binder, and the order of raising the temperature to the slurry discharge temperature are not particularly limited, but in order to make the dissolved amount of the slurry gas more than the saturation amount at the slurry discharge temperature, It is preferable to add an organic polymer binder to a low temperature solvent, mix and heat to prepare a binder solution, and mix the binder solution with a finely powdered adsorbent to obtain a slurry.

  More specifically, the temperature is raised while stirring the mixed solution in which the gas is dissolved at a temperature lower than the temperature at which the slurry is discharged, and containing an organic polymer binder and a solvent, to a temperature at which the slurry is discharged, Obtain a binder solution in which the organic polymer binder is dissolved and the ratio of dissolved gas amount to gas saturation amount is increased (binder solution preparation step), and while stirring the binder solution, the finely powdered adsorbent is foamed on the liquid surface It is preferable to obtain a slurry by adding in a plurality of times in a divided manner so as to suppress the above (slurry preparation step) and to easily obtain a uniform slurry with high viscosity in a short time at a relatively low temperature. Hereinafter, this aspect will be described in detail.

(Binder solution preparation process)
The solubility of a gas in a solvent is generally smaller at higher temperatures. Therefore, the organic polymer binder is added to a solvent with a large amount of dissolved air at a temperature lower than the discharge temperature of the slurry (for example, room temperature (25 ° C. or less)), and the organic polymer binder is dissolved by slowly stirring and heating. By raising the temperature to a predetermined temperature (for example, the discharge temperature of the slurry), it is possible to prepare a binder solution in which the ratio of the amount of dissolved gas to the amount of gas saturation is increased.

  It is also possible to prepare a solvent with a high amount of dissolved air by dissolving air in a solvent under pressure with an air compressor or the like beforehand in a solvent before adding the organic polymer binder. In this case, it is preferable to stir so that foaming of the liquid level does not occur. When the agitation is too intense and foaming becomes remarkable, a bubbled solvent is obtained by foaming, but the bubbles coalesce into the solvent, resulting in the same adverse effect as the degassing operation, and in the solvent Air content decreases. In this case, there is a tendency that the bubbles which are united and enlarged become defects of the molded body, or the slit is difficult to be formed due to the degassing effect. For example, when the stirring blade is a common two-blade (half-moon type) for axial flow stirring, if the rotation speed of the stirring blade exceeds 500 rpm, foaming on the liquid surface becomes remarkable, so less than 500 rpm is preferable, 350 rpm or less Is more preferable, and 300 rpm or less is particularly preferable.

  The amount of the organic polymer binder used in the preparation of the binder solution is usually such that the content in the obtained hollow fiber membrane-like adsorbent is from 20% by weight to 30% by weight based on the total weight (after drying). It is preferable to use an amount of 20% by weight to 25% by weight. When the content is higher than the lower limit, it is preferable in that a hollow fiber membrane-like adsorbent having mechanical strength sufficient to withstand continuous pressure filtration can be obtained. In addition, when the content is less than the upper limit, it means that the content of the fine powdery adsorbent is increased, and thus it is preferable from the viewpoint of reaction efficiency. Since the content of the organic polymer binder in the hollow fiber membrane adsorbent is usually such that the solvent is removed in the spinning step, the weight of the slurry (a mixture containing the organic polymer binder, the fine powder adsorbent and the solvent) is used. The amount of the organic polymer binder used is the value obtained by subtracting the weight of the solvent from the above, ie, the sum of the organic polymer binder used and the finely powdered adsorbent.

  The amount of the solvent used in the preparation of the binder solution is appropriately determined depending on the kind of the fine powdery adsorbent from the viewpoint of adjustment of viscosity and easiness of spinning described later by an amount that the organic polymer binder can be completely dissolved in the solvent. Be done. For example, when the fine powdery adsorbent is a zeolite, it is preferable that the concentration of the organic polymer binder in the spinning slurry is between 7% and 20%. When the concentration of the binder solution is higher than the lower limit, the slurry is not dispersed in the discharge of the core liquid or in the coagulation bath, and the formation of the compact by liquid phase separation is facilitated. When the concentration of the binder solution is lower than the upper limit, adjustment of a uniform slurry with the fine particles is easy, and defects in the molded body are less likely to occur.

  The temperature of the binder solution is not particularly limited as long as it is a temperature at which the entire amount of the organic polymer binder dissolves in the solvent above the melting point of the solvent, but from the viewpoint of safety when heating the solvent, a temperature below the flash point Is preferred. Furthermore, since the fluidity of the slurry is low below the Tg (glass transition temperature) of the organic polymer binder, a temperature above Tg is preferred. Specifically, the dissolution temperature at which the organic polymer binder is dissolved in a solvent is preferably 20 ° C. to 80 ° C., preferably 30 ° C. to 50 ° C., and more preferably 40 ° C. to 50 ° C.

  When dissolving the organic polymer binder in a solvent, the method of mixing at a temperature lower than the dissolving temperature, such as room temperature, and slowly raising the temperature to the temperature of the binder solution is preferable because it is difficult to reduce the amount of gas dissolved in the solvent. As a temperature rising rate, 5 ° C./min. To 1 ° C./min. And preferably 3 ° C./min. To 1 ° C./min. It is more preferable that

  The stirring time is not particularly limited as long as the organic polymer binder is dissolved in the solvent, but the stirring is preferably continued for 1 hour or more.

  The stirring speed at the time of dissolving the organic polymer binder is preferably adjusted so that foaming of the liquid surface does not occur. If the number of revolutions of the stirring blade is too fast and the foaming becomes remarkable, the bubbles merge into the solution and drop out, resulting in the same adverse effect as the degassing operation. Specifically, when the stirring blade is a common two-blade (half-moon type) for axial flow stirring, if the rotation speed of the stirring blade exceeds 500 rpm, foaming on the liquid surface becomes remarkable, so less than 500 rpm is preferable. 350 rpm or less is more preferable, and 200 rpm or less is particularly preferable.

(Slurry preparation process)
In the slurry preparation step, a fine powdery adsorbent is added to the binder solution prepared in the binder solution preparation step and the mixture is stirred to give a viscosity of 1.0 Pa.s. s or more 6.5 Pa. Prepare a spinning slurry of s or less (slurry discharge temperature). The viscosity of the spinning slurry can be adjusted by the ratio of the organic polymer binder, the finely powdered adsorbent and the solvent, and the temperature of the spinning slurry. When the ratio of the organic polymer binder to the solvent is large, the viscosity tends to be high. In addition, when the temperature of the spinning slurry is high, the viscosity tends to decrease.

  The amount of the fine powder adsorbent used is usually 70% by weight to 80% by weight of the content of the fine powder adsorbent in the obtained hollow fiber membrane adsorbent to the total weight of the hollow fiber adsorbent The amount is If the content of the fine powdery adsorbent in the hollow fiber membrane-like adsorbent is larger than the lower limit, it is preferable from the viewpoint of reaction efficiency. Since the solvent used for preparation of the spinning slurry is usually removed in the spinning step etc., the weight of the fine powder adsorbent to the total of the fine powder adsorbent and the organic polymer binder in the slurry for spinning is 70 weight The hollow fiber membrane adsorbent having a content of fine powdery adsorbent of 70% by weight to 80% by weight based on the total weight of the hollow fiber membrane adsorbent can be obtained by setting it to 80% by weight. it can.

  The finely powdered adsorbent is preferably used in a dry state. In addition, it is preferable to add the finely powdered adsorbent little by little to the binder solution and disperse it. Thus, when the fine powdery adsorbent is added, it is easy to obtain a slurry having a high viscosity and a uniform viscosity in a short time at a relatively low temperature.

  In the slurry preparation step, stirring is performed to disperse the fine powdery adsorbent. The stirring speed at this time is preferably adjusted so that foaming does not occur on the liquid surface. If the agitation is too vigorous and foaming becomes pronounced, the bubbles coalesce out during slurry preparation, resulting in the same negative effect as degassing the spinning slurry. For example, when the stirring blade is a common two-blade (half-moon type) for axial flow stirring, if the rotation speed of the stirring blade exceeds 500 rpm, foaming on the liquid surface becomes remarkable, so less than 500 rpm is preferable, 350 rpm or less Is more preferable, and 300 rpm or less is particularly preferable.

  The stirring temperature is preferably such that the temperature finally becomes the slurry temperature of the spinning process. The temperature of the obtained slurry is not particularly limited, but is preferably a temperature not lower than the melting point of the solvent and lower than the flash point, for example, dimethylsulfoxide or normal methyl pyrrolidone preferably 20-80 ° C, 30 ° C-50 ° C. It is more preferable that it is, and it is especially preferable that it is 30 to 45 degreeC.

  The stirring time is not particularly limited as long as it is the time for the finely powdered adsorbent to be uniformly dispersed in the slurry, but is preferably 5 hours or more, and more preferably 8 hours (overnight) or more. If the stirring time is short, particularly when the particle size is 1 μm or less, even if the appearance is uniform, the dispersion of the particles in the binder solution may be insufficient and molding may not be possible.

  The viscosity of the spinning slurry was 1.0 Pa.s. s or more 6.5 Pa. Adjust to s or less. The viscosity tends to decrease as the proportion of the solvent increases. The lower limit of the viscosity of the slurry for spinning is 1.2 Pa.s. It is preferable that it is s or more, and 1.5 Pa.s. It is more preferable that it is s or more. The upper limit of the viscosity of the spinning slurry is 5.0 Pa.s. It is preferable that it is s or less, and 4.5 Pa.s. It is more preferable that it is s or less. If the viscosity of the slurry for spinning falls below the above-mentioned lower limit, in the later-described spinning process, the slurry discharge diameter of the nozzle is increased, and the outer diameter narrows even if the discharge diameter of the core liquid is narrowed. The discharge pressure of the liquid may be superior and a sufficient film thickness may not be obtained. Here, the viscosity of the slurry for spinning was determined by dividing the value measured using a viscometer (manufactured by A & D Corporation, tuning fork vibration viscometer SV-100) according to JIS Z 8803 by the density of the slurry for spinning It is a value (absolute value of viscosity), and is a viscosity at a temperature at which the spinning slurry is discharged in the spinning step.

(Spinning process)
In the method for producing a hollow fiber membrane-like adsorbent according to the present invention, in the spinning step, the slurry is produced using a dry-wet spinning apparatus provided with a double port nozzle having a core liquid outlet and a slurry outlet located on the outer periphery thereof. The spinning slurry is discharged from the discharge port, and the core liquid is discharged from the core liquid discharge port, and the coagulation bath liquid is provided with a free running distance, and the hollow bath-like adsorbent is obtained.

  The dry-wet spinning apparatus used in the present invention comprises a double-mouthed nozzle. The double port nozzle has a core liquid discharge port and a slurry discharge port located on the outer periphery thereof. The shape of the slurry discharge port corresponds to the cross-sectional shape of the hollow fiber membrane-like adsorbent. Since the outer diameter of the hollow fiber membrane adsorbent is generally smaller than the outer diameter of the discharge port of the nozzle, the outer diameter of the discharge port of the nozzle should be about 1.5 times the planned outer diameter of the molding Is preferred. In addition, the inner diameter of the hollow fiber membrane is generally larger than the diameter of the core liquid discharge port of the nozzle, so it is preferable to be smaller than the planned inner diameter.

  When the slurry is transferred to a dry-wet spinning apparatus, it is preferable to remove air bubbles of a size that can be removed by a strainer or the like.

  Preferably, the slurry is not subjected to a degassing operation such as vacuum degassing before the spinning step. If the slurry is subjected to a degassing operation prior to the spinning step, the viscosity of the slurry is reduced. As a result, the diameter of the obtained hollow fiber is reduced. In addition, a slit structure is difficult to be formed, and a dense structure in which particles of a fine powdery adsorbent are packed is formed, and the flexibility of the hollow fiber membrane adsorbent obtained is lowered. Therefore, depending on the type of the organic polymer binder, molding processing of a module or the like becomes difficult.

  In the case of using a slurry having a high concentration of fine particles to spin a thick hollow fiber membrane, if the width of the slurry discharge port is increased and the thickness of the discharged slurry is increased, the conventional degassed slurry can be obtained. Although the core liquid for coagulation hardly diffuses in the slurry, the slurry used in the present invention is easily dissolved in the slurry because a large amount of air is dissolved, and the core liquid is easily diffused in the slurry, and at the same time porosity increases during coagulation. By the air, the core liquid and the solvent coming out, the slit structure is easily formed in the hollow fiber membrane-like adsorbent.

  The slit structure is formed by diffusion of the core liquid to the slurry side in the free running portion between the slurry discharge port and the bath of the coagulation bath during the spinning process. Therefore, it is desirable that the diffusion of the core liquid to the slurry side be fast and that the tension of the core liquid be large. In the slurry, when the content of the fine powdery adsorbent is high and the particle gap is small, the diffusion channel of the core liquid will sew between fine particles. Therefore, it becomes difficult to form a slit structure, and it tends to coagulate from the outside in a coagulation bath without forming a slit structure. However, even if the content of the fine powdery adsorbent in the slurry is the same, the formation of the slit structure can be promoted by increasing the amount of gas dissolved in the slurry.

  In the spinning step according to the present invention, a free running distance is provided between the core liquid discharge port and the coagulation bath liquid. The free running distance is not particularly limited, but is preferably in the range of 5 cm to 20 cm. If the free running distance is longer than the above lower limit, the slit structure tends to get deeper. If the free running distance is shorter than the above upper limit, the outer diameter of the hollow fiber tends not to be too thin.

  The core liquid used in the present invention can be coagulated without separating the organic polymer binder and the finely powdered adsorbent in the slurry for spinning, and also has a surface tension capable of forming a slit structure at that time. There is no particular limitation as long as it is. As a core liquid, water or aqueous solution is mentioned, for example. The temperature of the core liquid is not particularly limited, but is preferably 20 ° C to 40 ° C, and more preferably 20 ° C to 35 ° C. Also, the core liquid can be degassed in advance.

  The coagulation bath liquid used in the present invention is a liquid different from the solvent in the spinning slurry, and is a liquid that coagulates the spinning slurry. Specifically, it is a liquid that does not dissolve the organic polymer binder and can be compatible or mixed with the solvent. More specifically, water, alcohol and aqueous solution can be mentioned. The temperature of the coagulation bath liquid is not particularly limited, but is preferably 20 to 50 ° C., and more preferably 30 to 45 ° C. Thereby, the fine powdery adsorbent can be formed into a multi-purpose porous body having macropores of submicron to several micron diameter.

  The slurry discharge temperature is not particularly limited, but the temperature at which the spinning slurry and the core liquid are discharged causes dissolution of the dissolved air from the slurry to facilitate diffusion of the core liquid in phase separation caused by the spinning slurry coming into contact with the core liquid. And a temperature at which a macro slit-like structure is formed inside the hollow fiber membrane-like adsorbent, specifically, preferably 20 ° C. to 80 ° C., and more preferably 30 ° C. to 50 ° C. Since the viscosity tends to decrease as the slurry discharge temperature increases, the viscosity can also be adjusted by the temperature.

  The hollow fiber membrane-like adsorbent obtained by the production method of the present invention can recover its flexibility by immersion in alcohols after low-temperature drying at 60 ° C. or lower. Since heating at 150 ° C. or higher tends to lose flexibility, it is preferable to store and process at less than 150 ° C. The hollow fiber membrane-like adsorbent can be used with its flexibility maintained if it is stored in water or alcohol as it is without drying.

The hollow fiber membrane-like adsorbent obtained by the production method of the present invention has a high content of fine powdery adsorbent, is thick and at the same time has a large internal surface area due to the inner slit structure, Against pressure resistance, and also flexibility against bending that can be modularized and viscosity against liquid 7 g / cm ² / h. It has the above filtration performance. Therefore, hollow fiber membrane adsorbents can be bundled to form a hollow fiber membrane module for removing and extracting specific components.

  The hollow fiber membrane-like adsorbent obtained by the production method of the present invention can be continuously reacted with specific components under flowing conditions to remove or extract it. For example, the reaction activity of the hollow fiber membrane adsorbent is 60% or more of the fine powder adsorbent of the raw material. In addition, the reaction efficiency which can be industrially useful, the filtration throughput per unit time, the flexibility which can be modularized, and the continuous use / renewable durability can all be compatible. That is, according to the manufacturing method of the present invention, the contradictory conditions of increasing the pressure resistance and the amount of filtration processing simultaneously while increasing the mixing amount of the adsorbent, that is, reducing the amount of the organic polymer binder A hollow fiber membrane-like adsorbent which is compatible with this, is obtained

  The hollow fiber membrane-like adsorbent, for example, can continuously reduce 4MI of 80% or more from the raw material containing 4methylimidazole (4MI) in the production process of caramel beverage. In addition, it can be used for removing harmful ions and particulates in waste water.

(Example)
Next, the present invention will be described in more detail based on examples, but the present invention is not limited at all by the following examples and the like.

The physical properties were measured by the following method.
(1) Fine Powdered Adsorbent Content of Hollow Fiber Membrane Adsorbent The TG-DTA measurement is carried out from the weight loss ratio of the organic polymer binder by calcination.
(2) The outer diameter, the inner diameter, the film thickness, and the cross-sectional structure of the hollow fiber membrane adsorbent are confirmed by measurement with a caliper or SEM observation.
(3) Flexibility The breaking elongation at the time of tensile test is used as an index. The test piece at the time of the tensile test has an effective length of 80 mm, and the tensile speed is 10 mm / min. I did it.
(4) Pore Volume, Porosity, Pore Distribution Measurement was carried out by a mercury injection method using a mercury porosimeter (manufactured by Micromeritics, Autopore IV 9500).
(5) Slurry viscosity The slurry viscosity is a value obtained by dividing the value measured using a viscometer (a tuning product vibration viscometer SV-100, manufactured by A & D Co., Ltd. according to JIS Z 8803) by the density of the slurry (viscosity (Absolute value of) was used. The temperatures measured are also described. In addition, the density of the slurry of an Example and a comparative example was 1.26-1.33 g / cm < ³ >.

Example 1
Dimethyl sulfoxide (Wako Pure Chemical Industries, Ltd., special grade) 155. 25.0 g of polyethylene polyvinyl alcohol copolymer resin (Kuraray Co., Ltd., Eval G 156 B, melting point 160 ° C., Tg 50 ° C., pellet) as an organic polymer binder as a solvent Mixed with 3 g of air taken in at room temperature (25 ° C.) and atmospheric pressure (0.1013 MPa) to obtain a mixed solution in which air is dissolved in saturation, and a half-moon type two-blade impeller for axial flow stirring (Freon industrial stock While stirring at 200 rpm to 300 rpm, using an all PTFE-coated stirring bar (with blades) F-4012-001), slowly raise the temperature to 43 ° C. (heating rate: 3 ° C./min.) So as not to foam the liquid surface. The mixture was further stirred for 3 hours to completely dissolve the polyethylene polyvinyl alcohol copolymer resin to obtain a solution.

The resulting solution is heated and stirred as it is at 43 ° C., and as a fine powdery adsorbent, synthetic high silica zeolite powder (Tosoh Corp. HSZ-820 NHA, particle diameter 5 μm, crystal particle diameter 0.1 to 10) 0.5g, which was previously dried at 120 ° C for one night or more was used.) 100g was added little by little with a funnel so as not to foam the liquid surface, and the liquid surface was not bubbling still overnight The mixture was stirred to prepare a slurry for forming a porous body with a high amount of dissolved air. At this time, the concentration of the fine powdery adsorbent in the slurry is 36% by weight, and the amount of the fine powdery adsorbent charged in the hollow fiber membrane-like adsorbent is 80% by weight. Moreover, the viscosity of the obtained slurry after stirring overnight is 2.6 Pa.s at 43 ° C. It was s (density 1.29 g / cm < ³ >).

  Thereafter, the obtained slurry (43 ° C.) and water (34 ° C.) to be the core liquid are placed in separate containers connected to a cylinder pump, respectively, and set in the dry-wet spinning apparatus to set the core liquid discharge aperture 0 The core solution was flowed at a flow rate of 19.0 ml / min. At a flow rate of 21 cm / s, the slurry was flowed at a flow rate of 32 ml / min. The hollow fiber membrane-like adsorbent 1 was obtained by injecting into a 43 ° C. water bath at a free flow distance of 5 cm at a flow velocity of 2 cm / s and forming a hollow fiber membrane.

  The produced hollow fiber membrane-like adsorbent 1 had an outer diameter of 2.8 mm, an inner diameter of 1.0 mm, and a film thickness of about 0.9 mm, and had a large number of slit structures inside (FIG. 1). The slit structure is considered to be generated by the diffusion of the core liquid into the slurry and the air leached out of the slurry during phase separation of the spinning process. After drying the hollow fiber membrane-like adsorbent 1 at 160 ° C. overnight, the pore volume and pore distribution were measured. It was a multi-purpose porous body having macropores in the range of 0.3 to 13 μm with a pore volume of 1.2 mL / g. The content of the fine powdery adsorbent in the hollow fiber membrane-like adsorbent 1 is 77% by weight calculated from the loss due to the decomposition of the organic polymer binder by thermal analysis. Moreover, the breaking elongation at the time of a tension test was flexible with 12%, and a water flow test and module processing were possible. The viscosity of the slurry, the physical property values of the hollow fiber membrane adsorbent 1, etc. are shown in Table 1.

(Example 2)
In Example 1, the temperature after the temperature rise of the solution of the organic polymer binder and the temperature of the slurry are 46 ° C. (slurry viscosity; 2.3 Pa · s at 46 ° C.), and the drying temperature of the fine powdery adsorbent is 60 ° C. And 25.0 ml / min of water at 36 ° C. as a core liquid. A hollow fiber membrane adsorbent 2 was obtained in the same manner as in Example 1 except that the reaction was carried out.

  The hollow fiber membrane-like adsorbent 2 thus prepared has an outer diameter of 3.0 mm, an inner diameter of 1.4 mm, a film thickness of about 0.8 mm, and is dried overnight at 60 ° C., and then has a pore volume of 0.9 mL as measured by a mercury porosimeter. It was a multi-purpose porous body having macropores in the range of 0.4 to 7.3 μm at not less than 1 / g. The content of the fine powdery adsorbent in the hollow fiber membrane adsorbent is 72% by weight, as calculated from the loss due to the decomposition of the organic polymer binder, by thermal analysis. Moreover, the breaking elongation at the time of a tension test is 10%, and a water flow test and module processing were possible. The viscosity of the slurry, physical property values of the hollow fiber membrane-like adsorbent 2 and the like are shown in Table 1.

(Example 3)
Large room temperature (25 ° C) · 180.5 g of dimethyl sulfoxide (Wako Pure Chemical Industries, Ltd., special grade) as a solvent, 30.0 g of polyether sulfone (Solvay Advanced Polymers, Inc., Veradel 3000P) as an organic polymer binder Under air pressure (0.1013MPa), the mixture is mixed while taking in air to obtain a mixed solution in which the air is dissolved, and the temperature is slowly raised to 50 ° C so as not to foam the liquid surface while stirring at 200rpm to 300rpm. The temperature was increased at a rate of 3 ° C./min., And the mixture was further stirred for 3 hours to completely dissolve the polyethylene polyvinyl alcohol copolymer resin to obtain a solution.

While the resulting solution was heated and stirred at 50 ° C. as it was, a finely powdered adsorbent (the same synthetic high silica zeolite powder as in Example 1 was previously dried at 60 ° C. overnight or more) was used. 100 g was added little by little so as not to foam the liquid surface, and the mixture was further stirred overnight to prepare a slurry for forming a porous body with a high amount of dissolved air. The concentration of the fine powdery adsorbent in the slurry at this time was 32% by weight, and the charged amount of the adsorbent to the hollow fiber membrane-like adsorbent was 77% by weight. After stirring overnight, the resulting slurry had a pressure of 2.4 Pa.s. s (density: 1.29 g / cm ³ ), using a double-opening nozzle with a core liquid discharge port of 0.7 mm and a slurry discharge port of 6.0 mm, 11.7 ml / min. , 40 ml / min. A hollow fiber membrane adsorbent 3 was obtained in the same manner as in Example 1 except that the solution was injected into a 42 ° C. water bath.

  The produced hollow fiber membrane-like adsorbent 3 had an outer diameter of 3.8 mm, an inner diameter of 1.5 mm, and a film thickness of 1.15 mm. After drying at 60 ° C. overnight, it was a multi-purpose porous body having a pore volume of 0.88 mL / g or more and a macropore in the range of 40 nm to 7 μm as measured by a mercury porosimeter. The content of the fine powdery adsorbent in the hollow fiber membrane adsorbent is 74% by weight as calculated from the loss due to the decomposition of the organic polymer binder according to the thermal analysis. Moreover, the breaking elongation at the time of a tension test is 35%, and a water flow test and module processing were possible. The viscosity of the slurry, the physical property values of the hollow fiber membrane adsorbent 3 and the like are shown in Table 1.

(Example 4)
A hollow fiber-forming slurry was prepared in the same manner as in Example 2 except that 20.5 g of an organic polymer binder and 81 g of a finely powdered adsorbent were used. The slurry viscosity at the time of spinning is 1.1 Pa.s at 46 ° C. It was s (density 1.26 g / cm < ³ >). The other adsorbents were formed into hollow fibers in the same manner as in Example 2. The obtained hollow fiber membrane-like adsorbent was a hollow fiber having a small outer diameter and a thin thickness, such as an outer diameter of 2.1 mm and a thickness of 0.3 mm. After drying at 60 ° C. overnight, the pore volume was 1.0 mL / g as measured by a mercury porosimeter, and it was a multi-purpose porous body having a porosity of 58% and macropores in the range of 0.4 to 1.3 μm. The content of the fine powdery adsorbent in the hollow fiber membrane adsorbent is 71% by weight as calculated from the loss due to the decomposition of the organic polymer binder according to the thermal analysis. Moreover, the breaking elongation at the time of a tension test was flexible with 15%. The viscosity of the slurry, the physical property values of the hollow fiber membrane adsorbent 4, etc. are shown in Table 1.

(Comparative example 1)
A slurry was prepared in the same manner as in Example 1 except that degassing was performed at 820 rpm for 30 minutes while preparing a slurry for molding and immediately before molding, and an adsorbent was molded into a hollow fiber shape to obtain a hollow fiber membrane adsorbent R1. Obtained. The slurry viscosity is 2.5 Pa.s at 43.degree. It was reduced to s (density 1.37 g / cm ³ ). The outer diameter of the obtained hollow fiber membrane-like adsorbent R1 was 2.6 mm and the thickness was 0.6 mm, and although the internal slit structure of the cross section was very shallow, it became a hollow fiber having a dense structure as a whole. . The breaking elongation at the time of the tensile test was about 5.0% and the flexibility was greatly reduced, and it could not be used for filtration work with processing and pressure supply of solution. The viscosity of the slurry, the physical property values of the hollow fiber membrane adsorbent R1, etc. are shown in Table 1.

(Comparative example 2)
The slurry is prepared in double volume, deaerated for 25 minutes in the dissolution process of the organic polymer binder, and deaerated while stirring at high speed over 800 rpm for 5 minutes when adding fine powdery adsorbent, and the slurry is discharged as a nozzle for spinning Using the one with a caliber of 3.8 mm, the discharge rate of the slurry is 90 mL / min. , Discharge rate of the core liquid 80 mL / min. In the same manner as in Example 2 except that the adsorbent was formed into a hollow fiber shape, a hollow fiber membrane adsorbent R2 was obtained. The obtained hollow fiber membrane-like adsorbent had an outer diameter of 2.5 mm and a thickness of 1.0 mm, and as shown in FIG. 4, the slit having the cross-sectional structure was in a collapsed state. The breaking elongation at the time of the tensile test became very brittle at around 2%, and the porosity also decreased to less than 50%, so that the solution could not be used for filtration work by pressure feeding. The viscosity of the slurry, physical property values of the hollow fiber membrane-like adsorbent 2 and the like are shown in Table 1.

(Examples 5 to 7: 4MI adsorption removal test)
A pilot scale membrane module (see FIG. 3) was produced by bundling ten hollow fiber membrane-like adsorbents 1 to 3 obtained in each of Examples 1 to 3 at a length of 30 cm. In each case, a 20% caramel aqueous solution was continuously passed through, a 4MI adsorption removal test was conducted, and a study was made on the continuous use of the module. The pouring test was conducted under cross flow conditions, and caramel aqueous solution was supplied at a constant pouring speed by internal pressure supply. At this time, a 1% sodium hydroxide aqueous solution was passed as washing and regeneration treatment of the module every time the filtered amount of the caramel aqueous solution reached 1200 to 1800 g. The results are shown in Table 2.

Claims (8)

A method for producing a hollow fiber membrane adsorbent, which comprises
The hollow fiber membrane adsorbent comprises a fine powder adsorbent and an organic polymer binder,
The content of the fine powdery adsorbent is in the range of 70% by weight to 80% by weight,
The content of the organic polymer binder is in the range of 20% by weight to 30% by weight,
The film thickness is in the range of 0.3 mm to 1.3 mm,
Has a radial slit structure inside,
The spinning slurry is discharged from the slurry discharge port using a dry-wet spinning apparatus provided with a double-opening nozzle having a core liquid discharge port and a slurry discharge port located on the outer periphery thereof, and from the core liquid discharge port The core solution is discharged, and the coagulation bath solution is provided with a free running distance and injected to obtain a hollow fiber membrane-like adsorbent;
In the slurry for spinning, the organic polymer binder is dissolved in a solvent, the finely powdered adsorbent is dispersed, and the viscosity is 1.0 Pa.s. s or more 6.5 Pa. The manufacturing method of the hollow fiber membrane-like adsorbent whose s or less and the dissolved amount of gas are more than the saturation amount in slurry discharge temperature.   The manufacturing method according to claim 1, wherein the amount of dissolved gas at the time of discharge of the slurry for spinning is larger than the amount of saturation at the slurry discharge temperature. The spinning slurry is
The temperature of the mixed solution containing the organic polymer binder and the solvent, the temperature is lower than the slurry discharge temperature, and the gas is dissolved, and the temperature is raised while stirring to the slurry discharge temperature. A binder solution preparing step of dissolving a binder in a solvent and obtaining a binder solution in which the ratio of the amount of dissolved gas to the amount of gas saturation is increased;
3. The slurry preparation process according to claim 1, wherein the fine powdery adsorbent is added in plural times so as to suppress foaming of the liquid surface while stirring the binder solution. The manufacturing method of the hollow fiber membrane adsorbent as described.   The method for producing a hollow fiber membrane-like adsorbent according to claim 3, further comprising a gas dissolving step of dissolving a gas in the solvent before the binder solution preparing step.   In the spinning step, the temperature at which the spinning slurry and the core liquid are discharged causes dissolution of the dissolved air from the slurry to facilitate diffusion of the core liquid during phase separation which occurs when the spinning slurry contacts the core liquid. The method according to any one of claims 1 to 4, wherein the temperature is such that a macro slit-like structure is formed inside the hollow fiber membrane-like adsorbent.   The organic polymer binder is a polyethylene polyvinyl alcohol copolymer resin or polyether sulfone, and the fine powdery adsorbent is a zeolite fine powder. The manufacturing method described in. The discharge temperature of the slurry is in the range of 20 ° C. to 80 ° C.,
The core liquid is water or an aqueous solution having a discharge temperature in the range of 20 ° C. to 40 ° C.,
The method according to any one of claims 1 to 6, wherein the coagulation bath liquid is water or an aqueous solution having a temperature in the range of 20 ° C to 50 ° C.   The manufacturing method according to any one of claims 1 to 7, wherein a breaking elongation of the hollow fiber membrane-like adsorbent is 10% or more.