JP2017186722A - Fiber material and purification column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber material excellent in a removal performance of an adsorbate and a purification column incorporating the same.SOLUTION: The fiber material comprises a blended fiber comprising a plurality types of solid fibers having a common cross-sectional shape. At least two types of the plurality types of fibers have a constitutional ratio of 5.0% or more in the whole blended fiber. When a fiber having a highest rate of increase in surface area represented by the following formula (1) is defined as fiber (max) and a fiber having the lowest is defined as fiber (min) among the plurality types of fibers having a constitutional ratio of 5.0% or more, the fiber (min) has a rate of increase in surface area that is lower than that of the fiber (max) by 3.0% or more. The fiber (max) and the fiber (min) have a constitutional ratio in the whole blended fiber of 30.0% or more and 8.0% or more, respectively. The fiber (max) (a) has a rate of increase in surface area of 1.20 or more and (b) is porous, and a pore specific surface area is 5 m/g or more: Rate of increase in surface area=(a circumference length in a fiber cross section)/(a circumferential length of a circle having the same cross sectional area as the fiber cross section)(1)SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fiber material capable of efficiently adsorbing a substance to be removed in a liquid to be treated, and a purification column incorporating such a fiber material.

  Conventionally, as a form of an adsorbent used in a purification column for removing a substance to be removed in a liquid to be treated by adsorption, porous beads are often used. The reason for this is that the bead-shaped adsorption carrier can be uniformly packed in the adsorption column, and therefore has an advantage that the blood flow is less biased and the column design is easy. On the other hand, as means for improving adsorption performance, increasing the surface area per volume of the adsorption carrier can be mentioned. However, when the adsorption carrier is in the form of beads, if the bead diameter is reduced in order to increase the surface area per volume of the adsorption carrier, the gap between the beads is narrowed. If it does so, channel resistance will become high and pressure loss will increase, and it will become difficult to flow a processed liquid. Further, since the beads used as the adsorption carrier are usually spherical, it cannot be said that the surface area per volume is inherently large compared to other shapes. That is, even if there is an adsorption capacity inside the beads, the adsorption sites may not be used effectively.

  A fiber is mentioned as a form of the adsorbent other than the beads, and it is considered to use a fiber having a normal circular cross section. Examples of the form include those in which a large number of fibers are inserted in a straight shape parallel to the axial direction connecting the opening portions on both sides of the column case, or those in which a knitted fabric is formed.

  So far, inventions related to purification columns containing hollow fibers and solid fibers have been disclosed (Patent Documents 1 and 2).

  So far, as described in Patent Documents 3 to 5, in the field of clothing, there is a technique of mixing different types of irregular cross-sectional shapes for the purpose of improving the feeling of swelling, that is, bulkiness. In the field of dialyzers and the like, an invention has been made in which yarns are crimped as in Patent Document 6 to prevent adjacent yarns from overlapping and sticking to each other.

Patent Document 7 describes an invention that suppresses drift by combining a circular hollow fiber membrane and a spacer filament having an irregular cross section.
Japanese Unexamined Patent Publication No. 2011-156022 JP 2010-148851 A JP 2002-220758 A JP 2004-263341 A JP 2002-194621 A JP 2012-115743 A JP 2008-155209 A JP 2000-225304 A

Kazuhiko Ishikiyama et al. JOURNAL OF COLORID AND INTERFACE SCIENCE, VOL. 171, 103-111 (1995)

  However, the cross-sectional shape of the fiber used in Patent Documents 1 and 2 is circular, and the adsorption performance is low because the surface area relative to the volume of the adsorbent is small. Here, a method in which the cross section of the fiber has a shape other than a circle, that is, a fiber having an irregular cross section is conceivable. However, when the filling rate of the yarn is increased for the purpose of improving the adsorption performance of the purification column, the profile of the circumscribed circle (the profile of the fiber cross-section in the circumscribed circle of the irregular-shaped cross section of the cross-section of the irregular-shaped cross section of the cross-section yarn) , Which will be described later), the adjacent yarns overlap each other and come into close contact with each other, resulting in a problem that the surface area is easily lost.

  In the inventions described in Patent Documents 3 to 5, there are problems of increasing the number of crimping steps and yarn breakage at that time, and the wave height due to crimping tends to decrease due to aging storage and deterioration over time. From the viewpoint of long-term stability of the product, it was not preferable. Moreover, there was no description about aiming at adsorption | suction of the removal target substance in a to-be-processed liquid. Also, since porous fibers are not used, the yarn is heated for the purpose of improving the feeling of swelling and lightness by utilizing the difference in shrinkage rate of the yarn. When the yarn is used, the porous structure may be destroyed by heat treatment or higher processing.

  In the invention described in Patent Document 7, when the liquid to be treated is allowed to flow only inside the hollow fiber membrane, the liquid to be treated comes into contact only with the inside of the hollow fiber, while the liquid to be treated is separated from the hollow fiber membrane. In the case where only the outer side is to be flowed, the liquid to be treated comes into contact only with the outer side of the spacer filament and the hollow fiber, so that the adsorption performance is lowered in any case. Moreover, although the method of introduce | transducing a to-be-processed liquid into the hollow fiber inner side and both outer sides continuously is also considered, since the flow path of a to-be-processed liquid becomes complicated or an increase in pressure loss is caused, it is unpreferable.

  There is also a method of flowing the treatment liquid simultaneously on both the inside and outside of the hollow fiber by sealing with mesh etc. without providing a partition at the end, but it is difficult to evenly distribute the flow rate inside and outside Yes, flow unevenness is likely to occur.

  In addition, for example, after flowing blood as a liquid to be treated, the blood remaining in the column is returned to the body using physiological saline (sometimes referred to as “returning blood”). Is unfavorable because there is concern over the occurrence of a phenomenon called residual blood in which a large amount of blood remains inside the hollow fiber when returning blood due to crushing of the hollow fiber or the like.

  In view of the above-described conventional technology, the problem to be solved by the present invention is to provide a fiber material and a purification column incorporating the same, which are excellent in the performance of removing an adsorbed substance.

In order to solve the above problems, the fiber material of the present invention has the following configuration. That is, it includes a mixed fiber having a plurality of types of solid fibers having a common cross-sectional shape, and at least two of the plurality of types of fibers have a composition ratio of 5.0% or more in the entire mixed fiber. Among the plurality of types of fibers having the constituent ratio of 5.0% or more, the fiber having the highest surface area increase degree represented by the following formula (1) is represented by the fiber (max) and the following formula (1). When the fiber having the lowest degree of surface area increase is defined as the fiber (min), the fiber (min) has a surface area increase degree of 3.0% or less lower than the fiber (max), and the fiber (max) The composition ratio in the whole fiber is 30.0% or more, the composition ratio in the whole of the mixed fiber of the fiber (min) is 8.0% or more, and the fiber (max) is (a) degree of surface area increase. 1.20 or more and (b) porous, fine A fiber material having a pore specific surface area of 5 m ² / g or more.
Increase in surface area = (perimeter in fiber cross section) / (circumference length in a circle having the same cross-sectional area as the fiber cross section) (1)
The purification column of the present invention has the following configuration. That is,
A purification column comprising a plastic casing and the fiber material, wherein the fiber material is arranged in a straight shape in an axial direction connecting both side openings of the case in the plastic casing, and a liquid to be treated is disposed at both ends of the plastic casing. A purification column having an inlet port and an outlet port attached thereto.

In the fiber material of the present invention, the fiber (max) preferably has a pore specific surface area of 10 m ² / g or more.

In the fiber material of the present invention, the fiber (min) is preferably porous and the pore specific surface area is preferably 5 m ² / g or more.

In the fiber material of the present invention, the fiber (min) preferably has a pore specific surface area of 10 m ² / g or more.

  In the fiber material of the present invention, the circumscribed circle occupancy Sfo represented by the following formula (2) in the fiber (min) is preferably 0.90 or less.

Circumscribed circle occupancy Sfo = Sf / So (2)
Here, Sf: cross-sectional area of the fiber cross section, So: area surrounded by a circumscribed circle of the fiber cross section.

In the fiber material of the present invention, the degree of deformation Do / Di in the fiber (min) is preferably 1.10 or more.
Here, Do: the diameter of the circumscribed circle of the fiber cross section, Di: the diameter of the inscribed circle of the fiber cross section.

  The fiber material of the present invention preferably has a surface area increase degree of the fiber (min) of 1.10 or more.

  In the fiber material of the present invention, the shape of the fiber cross section of the fiber (min) is preferably circular or elliptical.

  In the fiber material of the present invention, the fiber (max) preferably has a circle-equivalent diameter of 10 μm or more and 1,000 μm or less.

  In the fiber material of the present invention, the Sfo ratio Z obtained by dividing the circumscribed circle occupancy Sfo of the fiber (min) by the circumscribed circle occupancy Sfo of the fiber (max) is preferably 0.20 or more.

  In the fiber material of the present invention, the fiber diameter ratio Y expressed by dividing the equivalent circle diameter of the fiber (max) by the equivalent circle diameter of the fiber (min) is preferably 10.0 or less.

  The fiber material of the present invention is preferably composed of straight fibers.

  In the fiber material of the present invention, it is preferable that the mixed fiber is made of fibers having two kinds of cross-sectional shapes in common.

  In the fiber material of the present invention, the ratio of the fiber (max) to the fiber (min) is preferably 10: 1 to 1: 2.

  In the fiber material of the present invention, the fiber (max) and the fiber (min) are preferably formed of the same material.

  In the fiber material of the present invention, the material is preferably an ester group-containing polymer.

  The fiber material of the present invention is preferably used for medical purposes.

  The fiber material of the present invention is preferably used for a purification column.

The fiber material of the present invention preferably has an adsorption amount of β ₂ -microglobulin of 0.005 mg / cm ³ or more.

  ADVANTAGE OF THE INVENTION According to this invention, the fiber material which uses the fiber which can adsorb | suck efficiently the removal target substance in a to-be-processed liquid, and the purification | cleaning column incorporating such a fiber can be provided.

The fiber sectional view for explaining an inscribed circle and a circumscribed circle. It is a figure of a nozzle | cap | die for manufacturing the fiber of 3 protrusions, and is a figure explaining each site | part of a nozzle | cap | die. FIG. 3 is a cross-sectional view of a fiber with three protrusions manufactured using the base of FIG. 2. The figure of a nozzle | cap | die for manufacturing the fiber which a cross section is close to a rod shape as a whole, and has a circular shape partially. The figure of the nozzle | cap | die for manufacturing the fiber whose cross section is cross shape. The figure of a nozzle | cap | die for manufacturing the fiber whose cross section is star shape. The circuit diagram at the time of adsorption | suction performance measurement of a column.

  The fiber used by this invention consists of a fiber which takes the shape and form of the fiber which does not have a hollow part called a solid fiber. In the case of a hollow fiber, the above-mentioned problems are concerned, so that it is not suitable.

  As the form of the fibers constituting the fiber material in the present invention, single fibers are preferable, and solid single fibers may be bundled as they are. A multifilament in which a plurality of single fibers are entangled to form a single yarn may be used, but this is not preferable because the entangled portion is difficult to come into contact with the liquid to be treated. In addition, the multifilament here includes both those composed of the same fiber and those composed of different types of fibers.

In the present invention, a fiber material having a plurality of types of solid fibers having a common cross-sectional shape is used. By mixing a plurality of types, it is possible to utilize various characteristics by combining them in various ways, and it is possible to supplement the shortcomings of one type of fiber with another type of fiber. One of the preferable effects is that by selecting a fiber having a relatively large surface area per volume as at least one kind of fiber, a high adsorption performance can be expected, and another fiber having a common cross-sectional shape is used. It is possible to prevent a phenomenon in which fibers having a large surface area per volume overlap and adhere closely to each other. From this point of view, controlling the degree of increase in the surface area of the solid fiber is one factor. Here, the surface area increase degree is a value represented by the following equation (1).
Increase in surface area = (perimeter in fiber cross section) / (circumference length in a circle having the same cross-sectional area as the fiber cross section) (1)
The method for measuring the degree of surface area increase is described below. Both ends of the fiber to be measured are fixed with a tension of about 0.1 g / mm ² and cut at random positions. Thereafter, the cut surface is enlarged with an optical microscope, DIGITAL MICROSCOPE DG-2 manufactured by SCARA, and photographed. When shooting, the scale is also shot at the same magnification. Using the image analysis software “Micro Measurement ver. 1.04” of SCARA Co., Ltd., the circumference and cross-sectional area of the fiber cross section are measured by tracing the outer circumference of the cross section of the yarn. This measurement is performed at 50 locations, the values are averaged, and the value obtained by rounding off the second decimal place is defined as the surface area increase degree.

  When fibers having the same cross-sectional shape used in the present invention are compared, the fibers having protrusions on the outer periphery of the cross-section are said to have the same shape as the fibers having no protrusions. Absent. When the number of protrusions is different, the shape is not said to be common. Even if the number of protrusions is the same, when the degree of surface area increase differs by 30% or more, the shape is not said to be common. Among fibers having no protrusions, round cross-section fibers and elliptic cross-section fibers have a surface area increase of 30% or more different from those of the same round cross-section fibers and elliptic cross-section fibers, or will be described later. When the degree of irregularity differs by 50% or more, the shape is not said to be common. In addition, a fiber having a round or elliptical cross section is not said to have a common shape as compared with a square fiber, and is not said to have a common shape when the number of corners is different among fibers having a square cross section. Moreover, even if the fibers have a square cross section with the same number of corners, they are not said to have a common shape when the degree of surface area increase differs by 30% or more. For example, if the fiber cross section is circular or elliptical, the number of protrusions is 0. If the fiber cross section is L, the number of protrusions is 2. If the shape is Y or T, the number of protrusions is 3. If there are 4 projections, 5 in the case of a star shape, and 6 projections in the case of a water shape.

  In the present invention, the yarn having the highest degree of surface area increase is called fiber (max) among the fibers sharing two or more kinds of cross-sectional shapes present as 5.0% or more as a constituent ratio in the entire mixed fiber. Such fibers (max) have a composition ratio of 30.0% or more in the entire mixed fiber, preferably 45.0% or more, more preferably 55.0% or more. If the composition ratio of the fiber (max) is less than 30.0%, improvement in adsorption performance cannot be expected. When a plurality of yarns having the highest degree of surface area increase are present, a fiber having a cross-sectional shape having a higher circumscribed circle occupancy described later is defined as a fiber (max) used in the present invention.

  The higher the surface area increase of the fiber (max) is, the more the surface area per volume is increased and the adsorption performance is improved. Therefore, the lower limit of the surface area increase of the fiber (max) is 1.20 or more, more preferably 1.35 or more, particularly preferably 1.45 or more. If the lower limit of the surface area increase degree of the fiber (max) is less than 1.20, the adsorption performance becomes insufficient. The upper limit of the increase in the surface area of the fiber (max) is preferably 6.6 or less, more preferably 4.5 or less, and particularly preferably 3.6 or less. When the upper limit of the increase in the surface area of the fiber (max) is within this preferred range, the strength and elongation of the fiber are not lowered, the spinning stability is maintained, and the fiber shape can be easily maintained. In addition, when the spinning solution before being formed into fibers is quickly cooled using wind or liquid, the protrusions on the fiber cross section do not excessively obstruct the flow of the wind or liquid, and the microstructure such as the fiber shape and pore diameter Are less likely to cause unevenness.

Here, the composition ratio in the whole of the mixed fiber is the cross section included in all the fibers in the cross section obtained by cutting the fiber material at an arbitrary position as represented by the following formula (2). This is the ratio of the number of common fibers.
Composition ratio (%) in the entire mixed fiber material = number of fibers having a common cross section (number) / total number of fibers (number) × 100 (2)
Moreover, the surface area increase degree is the lowest among a plurality of types of cross-sectional shape fibers having a composition ratio of 5.0% or more in the entire mixed fiber, and the surface area increase degree is 3.0 compared to the fiber (max). % Or lower fiber is referred to as fiber (min). By containing 8.0% or more of the fibers (min) as a constituent ratio of the entire mixed fiber, an effect of suppressing adhesion between the fibers (max) can be obtained. The composition ratio of the fibers (min) in the entire mixed fiber is preferably 12.0% or more, more preferably 16.0% or more, and further preferably 23.0% or more. The upper limit of the constituent ratio of the entire mixed fiber of fibers (min) is preferably 70% or less, more preferably 60% or less, still more preferably 52% or less, and particularly preferably 36% or less. If the upper limit of the composition ratio of the mixed fibers of the fibers (min) is within this preferable range, the surface area amount as the fiber material is sufficient, and the adhesion between the fibers (min) hardly occurs, and the adsorption performance is improved. Kept. When there are a plurality of yarns having the lowest degree of surface area increase, the fiber having a cross-sectional shape with a lower circumscribed circle occupancy (to be described later) is defined as a fiber (min) used in the present invention.

In the present invention, control of the degree of deformation of solid fibers may be important. The degree of irregularity referred to here is the ratio of the diameter of the inscribed circle to the circumscribed circle when the fiber cross section is observed, that is, the diameter Di of the inscribed circle and the diameter Do of the circumscribed circle according to the following equation (3). The value represented.
Deformity = Do / Di (3)
In the present invention, the lower limit of the degree of irregularity of the fiber (min) is preferably 1.10, more preferably 1 considering that the composition ratio of the fiber (min) in the entire mixed fiber is 8.0% or more. .20 or more, more preferably 1.60 or more, and particularly preferably 2.10 or more. When the lower limit of the degree of deformation of the fiber (min) is within this preferable range, the bulky effect of the entire fiber material is maintained. On the other hand, the upper limit of the degree of deformation of the fiber (min) is preferably 6.00 or less, more preferably 5.00 or less, and particularly preferably 3.80 or less. When the upper limit of the degree of deformation of the fiber (min) is within this preferable range, the bulkiness combined with the fiber (max) is appropriate, and it is easy to handle as a fiber material, and insertion into a case or the like is easy. In addition, the strength and elongation of the fiber do not decrease, the spinning stability is maintained, and the fiber shape can be easily maintained. Furthermore, when the spinning dope before being formed into fibers is quickly cooled using wind or liquid, the protrusions on the fiber cross section do not excessively obstruct the flow of the wind or liquid, and the microstructure such as the fiber shape and pore diameter Are less likely to cause unevenness.

  Here, the irregular cross-section may be a shape that retains symmetry such as line symmetry and point symmetry, or may be asymmetric, but is generally symmetric in terms of having uniform fiber properties. The shape is preferred. When it is determined that the irregular cross-section generally retains line symmetry and point symmetry, the inscribed circle is a circle inscribed in the curve that defines the fiber in the fiber cross section, and the circumscribed circle is the fiber cross section. Is a circle circumscribing the curve that outlines the fiber. FIG. 1 illustrates circumscribed circles, inscribed circles, and diameters Do and Di when a modified cross-section fiber having three protrusions is used.

  On the other hand, when it is determined that the deformed cross section is a shape that does not retain line symmetry or point symmetry at all, it is inscribed at least at two points with the curve that forms the outline of the fiber, and exists only inside the fiber, A circle having the maximum radius that can be taken in a range in which the circumference of the inscribed circle does not intersect with the curve forming the fiber outline is defined as the inscribed circle. On the other hand, a circle that circumscribes at least two points in the curve showing the contour of the fiber, exists only outside the fiber cross section, and has a minimum radius that can be taken in a range where the circumference of the circumscribed circle does not intersect the fiber contour. Yen.

  As a method of measuring the degree of irregularity, the photograph is cut, enlarged and photographed in the same procedure as the measurement of the degree of increase in surface area, and the diameter Do of the circumscribed circle and the diameter Di of the inscribed circle of the fiber cross section are determined using image analysis software. measure. And it calculates by the above formula (3). This measurement is performed at 30 locations, the values are averaged, and the value rounded to the second decimal place is defined as the degree of irregularity.

It is also preferable to control the circumscribed circle occupancy Sfo of the fibers (min) and fibers (max). The circumscribed circle occupancy is expressed by the following equation (4).
Circumscribed circle occupancy Sfo = (cross-sectional area Sf of fiber cross section) / (area So surrounded by circumscribed circle of fiber cross section) (4)
The fiber (max) can efficiently increase the surface area by increasing Sfo. On the other hand, the smaller the Sfo of the fiber (min), the smaller the occupied area of the fiber per unit cross-sectional area, so that the bulk can be increased. Therefore, the upper limit of Sfo of the fiber (min) is preferably 0.90 or less, more preferably 0.70 or less, and particularly preferably 0.50 or less. The lower limit of Sfo of the fiber (min) is preferably 0.05 or more, more preferably 0.15 or more. If the lower limit of the Sfo of the fiber (min) is within this preferred range, the high elongation of the fiber is not impaired. The Sfo ratio Z obtained by dividing the circumscribed circle occupancy Sfo of the fiber (max) by the circumscribed circle occupancy Sfo of the fiber (min) is preferably 0.20 or more, more preferably 0.40 or more, Preferably it is 0.80 or more, and particularly preferably 1.10 or more. By setting the Sfo ratio Z within this preferable range, the bulkiness can be obtained while efficiently increasing the surface area, and therefore, excellent adsorption performance as a fiber material can be exhibited.

  As a method of measuring the circumscribed circle occupancy, the fiber is cut, enlarged and photographed in the same procedure as the measurement of the profile, and the diameter Do of the circumscribed circle of the fiber cross section and the fiber cross section are measured using image analysis software. The cross-sectional area Sf is measured, and So is obtained from Do and calculated by the above equation (4). This measurement is performed at 30 locations, the values are averaged, and the value rounded to the second decimal place is taken as the circumscribed circle occupancy of the fiber.

  As the equivalent circle diameter of the fiber cross section, the fiber (max) and the fiber (min) are preferably substantially equal. Therefore, in the fiber material, the upper limit of the fiber diameter ratio Y obtained by dividing the equivalent circle diameter of the fiber (min) by the equivalent circle diameter of the fiber (max) is preferably 10.0 or less, and more preferably 3.0. Hereinafter, it is particularly preferably 1.4 or less. Further, the lower limit of Y is preferably 0.2 or more, more preferably 0.5 or more, and particularly preferably 0.7 or more. When the fiber diameter ratio Y is within this preferred range, there is no yarn that is easily damaged by impact or the like, and the surface area of the entire fiber material is not reduced.

  Regarding the absolute value of the equivalent circle diameter, the equivalent circle diameter of the fiber (max) is preferably 10 μm or more and 1,000 μm or less, and more preferably 20 μm or more and 500 μm or less. When the equivalent circle diameter of the fiber (max) is within this preferable range, the mechanical strength of the yarn is maintained and sufficient adsorption performance is obtained.

As a method of measuring the equivalent circle diameter, both ends of a yarn to be measured are fixed and cut in a state where a tension of 0.01 to 0.1 g / mm ² is applied. Thereafter, the cut surface is enlarged with an optical microscope, for example, the above-mentioned SCARA product or the like, and photographed. In that case, the scale is also photographed at the same magnification. After digitizing the image, the cross-sectional area S is calculated by tracing the outer periphery of the cross-section of the yarn using the above-mentioned image analysis software manufactured by SCARA, Inc. The equivalent diameter is calculated. Calculate the average of the 30 measured values and round off to the first decimal place.
Equivalent circle diameter of fiber cross section = 2 × (S / π) ^1/2 (5)
The fiber material in the present invention is not particularly limited, but organic materials are preferably used from the viewpoint of ease of molding and cost, and esters such as polymethyl methacrylate (hereinafter referred to as PMMA) and polyester. A group-containing polymer, polyacrylonitrile (hereinafter referred to as PAN), polysulfone, polyethersulfone, polyarylethersulfone, polypropylene, polystyrene, polycarbonate, cellulose, cellulose triacetate, ethylene-vinyl alcohol copolymer, and the like are used. Among them, it is preferable to include a material that is hydrophobic to some extent and has a property of adsorbing proteins and the like, and examples thereof include PMMA and PAN. PMMA and PAN are also representative examples of fibers having a uniform structure in the thickness direction, and are preferable because a structure having a uniform structure and a sharp pore size distribution can be easily obtained. A polymer containing an ester group such as the above PMMA is preferable because it is excellent in biocompatibility and easily develops a function by controlling a terminal group. In particular, PMMA is an amorphous polymer, is excellent in moldability and cost, and has high transparency. Therefore, the internal state of the fiber is relatively easy to observe, and it is easy to evaluate the fouling state.

  The fiber may also have a negative charge. It has also been reported that the inclusion of a functional group having a negative charge in at least a part of the material increases the hydrophilicity and tends to finely disperse (that is, many fine pores are formed). Materials having a substituent such as sulfo group, carboxyl group, phosphoric acid group, phosphorous acid group, ester group, sulfite group, hyposulfite group, sulfide group, phenol group, hydroxysilyl group as the functional group having negative charge Is mentioned. Among these, at least one selected from a sulfo group, a carboxyl group, and an ester group is preferable. As those having a sulfo group, vinyl sulfonic acid, acrylic sulfonic acid, methacryl sulfonic acid parastyrene sulfonic acid, 3-methacryloxypropane sulfonic acid, 3-acryloxypropane sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid and These sodium salts, potassium salts, ammonium salts, pyridine salts, quinoline salts, tetramethylammonium salts and the like can be mentioned. The negative charge amount is preferably 5 μeq or more and 30 μeq or less per 1 g of dried fiber. The negative charge amount can be measured using, for example, a titration method.

Moreover, the fiber (max) of the present invention is porous, and the adsorption performance of the substance to be adsorbed can be improved by controlling the pore specific surface area. Therefore, the lower limit of the pore specific surface area is 5 m ² / g or more. If the pore specific surface area is less than 5 m ² / g, the adsorption performance of the substance to be adsorbed cannot be improved. The lower limit of the pore specific surface area is preferably 10 m ² / g or more, more preferably 30 m ² / g or more, still more preferably 120 m ² / g or more, and particularly preferably 170 m ² / g or more. On the other hand, the upper limit of the pore specific surface area is preferably 1,000 m ² / g or less, more preferably 800 m ² / g or less, further preferably 650 m ² / g or less, particularly preferably 500 m ² / g or less. is there. When the upper limit of the pore specific surface area is within this preferable range, the mechanical strength is maintained. The fiber (min) may have a structure having no pores, but as described above, the adsorption performance can be improved by having a pore specific surface area equivalent to that of the fiber (max).

  As described in Non-Patent Document 1, the pore specific surface area is obtained by measuring the degree of freezing point by capillary aggregation of water in the pores by differential scanning calorimetry (DSC) measurement using a differential scanning calorimeter (DSC). Desired. In the measurement / calculation method, the description of Non-Patent Document 1 described above is referred to.

  The porous structure of the solid yarn is an important factor affecting the adsorption rate of the substance to be adsorbed. If the average pore radius is small, it becomes difficult for the substance to be adsorbed to enter the inside of the pores by diffusion, and the adsorption efficiency is lowered. On the other hand, if the pore radius is too large, the adsorbed substance is not adsorbed in the voids of the pores, and the adsorption efficiency is reduced. That is, there is an optimum pore size according to the size of the substance to be adsorbed to be removed, and if the pore diameter is selected incorrectly, the adsorbed substance cannot be adsorbed sufficiently. For these reasons, the average pore radius of the solid yarn should be in the range of 1 to 100 nm, and within this range, substances such as low-molecular substances, proteins, lipid aggregates such as proteins and low-density lipoproteins, etc. Can be adsorbed. The average pore radius when adsorbing and removing proteins is preferably 1 nm or more and 100 nm or less, more preferably 5 nm or more and 50 nm or less. The average pore radius of the porous fiber is determined by the differential scanning calorimetry using the differential scanning calorimeter (DSC) described in Non-Patent Document 1 as well as the pore specific surface area. It is obtained by measuring the degree of descent. For the measurement / calculation method, the description in Non-Patent Document 1 is referred to.

  In the fiber according to the present invention, the cross-sectional structure of the yarn is not particularly limited, but a fiber having a homogeneous structure is preferable because it has a homogeneous porous structure in the thickness direction of the fiber so that an adsorption area can be further secured. Here, heterogeneous structures having macrovoids are often seen in yarns produced by non-solvent induced phase separation. The macro void referred to here is a hole having a diameter of 25 μm or more. In the present invention, it is preferable that such a hole having a diameter of 25 μm or more does not exist, more preferably a hole having a diameter of 15 μm or more does not exist, and further preferably no hole having a diameter of 8 μm or more exists. Thus, if there is no void having a diameter larger than a specific size, the surface area per volume does not decrease, and the physical properties of the fiber can be maintained within a necessary range. However, the diameter here refers to the short diameter of the hole when the shape of the hole is other than a spherical shape, such as an egg shape.

  As a method for producing the fiber material of the present invention, any of conventionally known post-mixing method and spinning-mixing method can be applied. As the post-mixing method, fiber is supplied to the washing process and winding process of spinning, the method is mixed by air entanglement, the method is mixed by air entanglement, the method is mixed by twisting and combining, and the method is mixed by weaving. Examples thereof include, but are not limited to, a method of mixing, a method of mixing by knit, a method of dispersing and collecting in a liquid. Moreover, composite spinning is mentioned as a spinning fiber mixing system. For composite spinning, a method in which a plurality of yarns are simultaneously discharged and wound from the same base having a plurality of discharge holes, or a base having different discharge port shapes is mixed in a base discharge block by using a monohole base. By doing so, there is a method of simultaneously discharging and winding yarns having different cross-sectional shapes. In addition, post-mixing is more likely to be partially biased compared to the spinning and blending method, and if the cross-section of the fiber is viewed, it may be partially biased, resulting in stable quality as a fiber material. There is a problem with sex. In the case of the spinning and blending method, it is preferable that unevenness is hardly generated and the quality can be stabilized. It is also advantageous in that the combination of fiber shapes and the fiber mixing ratio can be easily changed by appropriately changing the configuration and arrangement of the base. In addition, the additive etc. may be added in the range which does not prevent the effect | action and effect in this invention.

  Moreover, it is preferable that a fiber (max) and a fiber (min) are the same raw materials. By doing in this way, the target adsorption | suction object substance can be more effectively removed as a fiber material which shares physical properties, such as a pore structure, and a chemical property. In addition, when spinning with a multi-spindle spinning machine, the same spinning stock solution is supplied, and the composition of the die to be discharged can be selected as appropriate, so that the fibers can be mixed from the stage of the die discharge, resulting in high productivity. .

  Further, the number of types of fibers having different cross-sectional shapes constituting the fiber material is preferably smaller from the viewpoint of productivity and control of the fiber material, preferably 4 types or less, more preferably It is 3 or less types, More preferably, it is comprised only from 2 types, a fiber (max) and a fiber (min).

  The ratio of the fibers (max) to the fibers (min) is preferably 10: 1 to 1: 2, more preferably 8: 1 to 1: 1, more preferably 5: 1 to 1: 1, particularly preferably. 3: 1 to 2: 1. Any combination from the upper limit to the lower limit of the ratio may be used. By doing in this way, it is thought that the surface area increase by a fiber (max) and the bulky effect by a fiber (min), ie, the dispersibility improvement of a thread | yarn, are compatible.

  Examples of the form and shape of the fiber material used in the present invention include woven fabric, knitted fabric, non-woven fabric, and straight shape. The types of woven fabrics include plain weave, twill weave, satin weave, Nanako weave, steep oblique weave, weft double weave, warp double weave and the like. The types of the knitted fabric include a flat knitted fabric, a Kanoko knitted fabric, a rib knitted fabric, a double-sided knitted fabric which are weft knitted fabrics. Examples of the nonwoven fabric include a short fiber nonwoven fabric, a long fiber nonwoven fabric, a nonwoven fabric obtained by a flash spinning method, and a nonwoven fabric obtained by a melt blow method. Among these, a knitted fabric is particularly preferable. This is because fiber waste is less likely to be generated and the size of the voids is less likely to vary and can be controlled easily. On the other hand, the straight shape can be easily inserted parallel to the axial direction connecting the openings on both sides of the column case, and the flow path of the liquid to be treated can be secured separately from the adsorbent, thus suppressing the flow resistance. It is preferable because it is advantageous with respect to adhesion of solutes in the liquid to be treated.

  As a method for converging the spun fibers, there are a method in which the fibers are wound once in a fisseur and then processed into a target shape, and a method in which the fibers are introduced into a processing apparatus as they are. There are parallel caskets, polygonal skeins, circular skeins, etc., but parallel caskets and polygonal skeins are preferred when obtaining straight fiber bundles.

  Although it is possible to improve the dispersibility of the yarn by using the fiber mixing technique according to the present invention, in order to improve the handleability of the fiber material after being wound with a fass, that is, the fibers of the fiber material are static electricity, etc. In order to prevent the rebound from being lost, the fiber material may be wound with a film, a net, a mesh, a nonwoven fabric or the like, or a thread called a covering thread may be wound around the fiber.

Beta ₂ of fiber material of the present invention - Micro glycidyl Brin (hereinafter, beta ₂ -MG) adsorption is preferably from 0.005 mg / cm ³ or more, more preferably 0.014 mg / cm ³ or more, more preferably 0. 020mg / cm ³ or more, and particularly preferably 0.026 mg / cm ³ or more. When the amount of adsorption of β ₂ -MG is within this preferable range, the column is packed. Even if the number of fibers to be packed is not increased, good adsorption performance is exhibited, the column volume does not increase, the cost is reduced, and the handleability is excellent. In particular, when blood is used as the liquid to be treated, the amount of blood taken out from the body does not increase, so that serious side effects such as a decrease in blood pressure are not caused.

The adsorption performance of the yarn can be easily measured in a batch as described below using β ₂ -MG, which is a causative protein of dialysis amyloidosis, which is a long-term dialysis complication, as an adsorption target. That is, first, the bovine blood to which sodium azide has been added is adjusted so that the hematocrit is 30 ± 3% and the total protein amount is 6.5 ± 0.5 g / dL. In addition, bovine plasma within 5 days after blood collection is used. Next, the β ₂ -MG concentration is added to 1 mg / L and stirred. Further, the length of the fiber material is adjusted so that the fiber material contains about 100 fibers and the volume of the fibers becomes 0.0905 cm ³ , and the fiber material is put into, for example, a 15 mL centrifuge tube manufactured by Greiner. 12 mL of the above bovine plasma is put therein, and using a Wave-SI manufactured by TAITEC, for example, a seesaw shaker, the scale is set to 38 and the angle is maximum (one reciprocation in 1.7 seconds), and at room temperature (20 to 25 ° C.). Stir for 1 h. In order to measure β ₂ -MG concentration C ₁ (mg / mL) before stirring and β ₂ -MG concentration C ₂ (mg / mL) after stirring, 1 mL each was sampled and stored in a freezer at −20 ° C. or lower. save. The β ₂ -MG concentration is measured by the latex agglomeration method, and the adsorption amount per fiber volume and the adsorption amount per fiber surface area are calculated from the following equation (6).
Adsorption amount per fiber volume (mg / cm ³ ) = (C ₁ -C ₂ ) × 12 / 0.0905 (6)
As the discharge shape of the spinneret for producing the fiber according to the present invention, those shown in FIGS. 2 and 4 to 7 can be used.

  The fiber material in the present invention can be used as a purification column by being incorporated in a casing having an inlet and an outlet for the treatment liquid.

  As the shape of the casing, both ends are open ends, and examples thereof include a rectangular cylinder and a cylindrical body such as a square cylindrical body and a hexagonal cylindrical body. Among these, a cylindrical body, particularly a cylindrical body having a perfect circular section is preferable. This is because the casing does not have corners, so that the retention of blood at the corners can be suppressed. Moreover, by making both sides open ends, the flow of the processing liquid is less likely to be turbulent, and pressure loss can be minimized. Moreover, it is preferable that a casing is an instrument comprised with a plastic, a metal, etc. Among these, plastic is preferably used from the viewpoints of cost, moldability, weight, blood compatibility and the like. In the case of plastic, for example, a thermoplastic resin excellent in mechanical strength and thermal stability is used. Specific examples of such thermoplastic resins include polycarbonate resins, polyvinyl alcohol resins, cellulose resins, polyester resins, polyarylate resins, polyimide resins, cyclic polyolefin resins, polysulfone resins, polyether sulfones. Resin, polyolefin resin, polystyrene resin, and mixtures thereof. Among these, polypropylene, polystyrene, polycarbonate, and derivatives thereof are preferable in terms of moldability and radiation resistance required for the casing. In particular, resins with excellent transparency, such as polystyrene and polycarbonate, are convenient for ensuring safety because the internal state can be confirmed during perfusion of blood, for example. Resins with excellent radiation resistance are used when radioactive irradiation is performed during sterilization. This is because it is preferable. The resin is manufactured by injection molding using a mold or by cutting a material.

  As a method for sealing the end of the purification column, there are a method of arranging a mesh and a method of providing a through hole that is fixed with resin and penetrates the partition wall to communicate the inside and outside of the casing. Here, the through hole is an opening that penetrates the partition wall in the fiber longitudinal direction. In other words, it is a hole that exists in and penetrates the partition wall and communicates the inside and outside of the casing. Among these, the method of arranging the mesh is more preferable because the process is easier than the method of forming the partition walls and the dispersibility of the liquid in the column is high. Further, for the purpose of further improving the dispersibility of the liquid to be treated in the column, a mesh having a large pressure loss due to a part of the mesh, or a plate for controlling a flow called a baffle plate or a baffle plate may be provided.

  The shape of the fiber material when incorporated in the column is preferably a straight shape as described above, but it is preferable to insert a straight-shaped fiber bundle substantially parallel to the axial direction connecting the opening portions on both sides of the column case. The straight-shaped fiber bundle is less likely to be turbulent because the liquid to be processed flows along the fibers, and easily distributes the liquid to be processed in the column. Further, the flow resistance can be suppressed, which is advantageous for an increase in pressure loss due to adhesion of a solute in the liquid to be treated. Therefore, even when high-viscosity blood is used as the liquid to be treated, the risk of coagulation in the casing can be kept small, and residual blood or the like is unlikely to occur. The number of straight fibers inserted into the column is preferably 1,000 to 500,000.

In the present invention, it is important to control the filling rate of fibers into the casing. The upper limit of the filling rate is preferably 70% or less, more preferably 65% or less, and still more preferably 62% or less. The lower limit of the filling rate is preferably 20% or more, more preferably 30% or more, still more preferably 39% or more, and particularly preferably 47% or more. The filling rate is the ratio of the casing volume (Vc) calculated from the cross-sectional area and length of the casing to the individual fiber cross-sectional area, casing length, and fiber volume (Vf) calculated from the number of fibers. It is calculated | required from 7)-(9) Formula.
Vc = Cross sectional area of casing body × effective length (7)
Vf = fiber cross-sectional area × number of fibers × effective length (8)
Filling rate = Vf / Vc × 100 (%) (9)
When the filling rate is within the above preferable range, it is easy to suppress the adhesion between yarns, and the insertion property into the case is also good. On the other hand, the fibers in the case are less likely to be biased, the flow in the column is less likely to be uneven, and the adsorption efficiency of the column can be maintained. In addition, when the liquid to be treated is blood, blood return is good and residual blood is difficult to remain. Although details of the blood return test will be described later, the amount of residual blood in the column during the test is preferably 5 mL or less, and more preferably 1 mL or less.

In addition, about the cross-sectional area of a casing trunk | drum, when a casing has a taper, it is set as the cross-sectional area in a casing center. In addition, Vc here does not include the volume of a member that does not contain a fiber, for example, a member that serves as an inlet / outlet port of a liquid to be processed that is not directly filled with a fiber, such as a header or a header cap. Shall. About Vf, when using the spacer fiber for preventing adhesion | attachment of fibers in a case, the volume is also included. The effective length of the fiber refers to the length obtained by subtracting the length of the partition wall from the casing length, and the upper limit of the effective length of the fiber may vary depending on the application, but the fiber is curved. Or 5,000 mm or less, more preferably 500 mm or less, and particularly preferably 210 mm or less, from the viewpoint of increasing pressure loss when columned. On the other hand, if the length is too short, the amount of fibers discarded when cutting excess fibers that have jumped out of the column in order to equalize the length of the fibers increases, which is not preferable. In addition, there are drawbacks such as difficulty in handling the fiber material. Therefore, the lower limit of the effective length of the fiber is preferably 5 mm or more, more preferably 20 mm or more, and particularly preferably 30 mm or more. As a method for measuring the effective length of the fiber, in the case of a crimped fiber or the like, the fiber length is measured in a straight shape with both ends of the fiber extended. Specifically, a piece of fiber taken out from the column is fixed with tape or the like and lowered vertically, and the other piece is given a weight of about 5 g per cross-sectional area (mm ² ) of the fiber so that the fiber is linear. Immediately measure the total length when it becomes. This measurement is performed for 100 fibers selected arbitrarily in the column, the average value of 100 fibers is calculated in mm, and the first decimal place is rounded off.

  Further, in the present invention, it has been found that the equivalent diameter of the channel cross section is important in order to increase the chance that the substance to be adsorbed contacts the solid yarn while the liquid to be treated passes through the column. Here, the flow path is a space in which the liquid to be treated can flow between solid yarns arranged substantially parallel to the longitudinal direction of the column, and the cross section of the flow path is perpendicular to the axial direction connecting the openings on both sides of the case. It is a cross section. The equivalent diameter represents the diameter when the channel cross section is considered to be circular, and specifically represents the width of the channel obtained by the following equation (10). The upper limit of the equivalent diameter of the channel cross section is preferably 250 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. The preferable lower limit of the equivalent diameter of the channel cross section is 10 μm or more, and more preferably 30 μm or more. If the equivalent diameter of the cross section of the flow path is within the above-mentioned preferable range, the opportunity for the adsorbed substance to contact the surface of the solid yarn can be sufficiently secured, while the pressure loss of the column is not excessively increased and blood is not easily activated. .

The equivalent diameter (D _p ) of the channel cross-section is obtained by the following equation (10) in the case of a fiber material composed of only one type of solid fiber having a common cross-sectional shape.
D _p = 4 × ((D _case / 2) ² − (D _fiber / 2) ² × N) / (D _case + D _fiber × N) (10)
Here, in the above formula (10), D _{case represents} the inner diameter of the column case, D _fiber represents the equivalent circle diameter of the fiber, and N represents the number of yarns.

In the case of a fiber material having a plurality of types of solid fibers having a common cross-sectional shape as in the present invention, the equivalent diameter (D _p ) of the channel cross section is obtained by the following equation (11).
D _p = 4 × ((D _case / 2) ² − (D _fiber−max / 2) ² × N _max − (D _fiber−min / 2) ² × N _min ) / (D _case + D _fiber−max × SA _max x N _max + D _fiber-min x SA _min x N _min ) (11)
Here, in the above formula (11), D _case : inner diameter of column case, D _fiber-max : equivalent circle diameter of fiber (max), D _fiber-min : equivalent circle diameter of fiber (min), N _max : fiber (Max) number of yarns, N _min : number of yarns of fiber (min), SA _max : degree of increase in surface area of fiber (max), SA _min : degree of increase in surface area of fiber (min).

  In the present invention, since the fiber (max) is porous, the protein enters the fiber and is adsorbed. Therefore, a fiber shape and a porous structure are required so that the protein can easily move to the inside of the fiber. Furthermore, in the present invention, it was found that increasing the pressure loss of the column makes it easier for the protein to move into the solid yarn. On the other hand, if the pressure loss is too large, blood will be activated. That is, the pressure loss when bovine blood flows through the column at a flow rate of 200 mL / min is 0.5 kPa or more, preferably 1.5 kPa or more, more preferably 3.0 kPa or more, while the upper limit is 50 kPa or less. And is preferably 40 kPa or less, more preferably 30 kPa or less, and particularly preferably 20 kPa or less. The pressure loss can be controlled by adjusting the filling rate of the solid yarn into the column, the case inner diameter, the solid yarn diameter, the number of solid yarns, and the like. A method for measuring the pressure loss will be described later. There are a wide variety of uses for such fiber materials and purification columns incorporating them, and they can be used for water treatment, purification, medical care, and the like. In particular, in the case of blood purification use in medical applications, there are two methods of treatment: direct perfusion of whole blood and separation of plasma or serum from blood followed by passage of plasma or serum through a column. The column can be used in any method.

  In addition, when used for extracorporeal circulation as a medical device, from the viewpoint of one-time processing amount and ease of operation, a method of incorporating adsorption into an extracorporeal circulation circuit and performing online adsorption removal is preferable. In this case, the purification column of the present invention may be used alone or may be used in series with an artificial kidney during dialysis. By using such a technique, it is possible to remove substances that are insufficiently removed only by an artificial kidney simultaneously with dialysis. In particular, the function of the artificial kidney can be complemented by adsorbing and removing large molecular weight substances that are difficult to remove with an artificial kidney using the purification column according to the present invention.

  When used simultaneously with the artificial kidney, it may be connected before the artificial kidney or after the artificial kidney in the circuit. The merit of connecting in front of the artificial kidney is that it is difficult to be affected by dialysis by the artificial kidney, so that the original performance of the purification column is easily exhibited. On the other hand, the merit of connecting after the artificial kidney is that the blood after the water removal by the artificial kidney is processed, so that the solute concentration is high and the adsorption removal efficiency can be expected to increase.

  In addition, by holding a drug or the like in the pores of the fiber material in advance, it is possible to provide a function such as releasing the drug or the like at the same time as adsorption. When used as a medical device as an example, antithrombogenicity can be enhanced by holding an anticoagulant in advance.

  In the following, an example of manufacturing a fiber material according to the present invention and a purification column incorporating the fiber material will be described.

<Production of fiber material>
A spinning dope prepared by dissolving the polymer in a solvent is prepared. At this time, as the stock solution concentration (concentration of the substance excluding the solvent in the stock solution) is lower, the pore diameter of the fiber can be increased. Therefore, the pore diameter can be controlled by appropriately setting the stock solution concentration. In addition, the pore diameter can be controlled by using a polymer having a negatively charged group. From this viewpoint, the preferred stock solution concentration in the present invention is 30% by mass or less, more preferably 27% by mass or less, and still more preferably 24% by mass or less. Such a stock solution is discharged from the die, passed through a dry air portion of a certain distance, and then discharged into a coagulation bath containing a poor solvent such as water or a non-solvent to solidify the fiber. Examples of the base are shown in FIG. 5 (slit width W = 0.10 mm, slit length L = 1.0 mm) and FIG. 4 (slit width W = 0.10 mm, slit length L = 1.0 mm). By using a die having a discharge port having such a modified cross-sectional shape and using the number of these two types of die in a ratio of 1: 1, for example, fiber mixing by spinning becomes possible. Here, it is preferable that the arc R is ½ of the slit width. In addition, as arrangement | positioning of a nozzle | cap | die, by making the thing of a different discharge port shape alternate, when making it into a fiber material, it can reduce that the irregular cross-section yarn which makes a cross-sectional shape common is collected. The discharged stock solution is obtained by passing it through a dry air portion of a certain distance and then discharging it into a coagulation bath made of a poor solvent such as water or a non-solvent. From the above viewpoint, the lower limit of the yarn passing (staying) time in the dry section is as described above. Further, when the structure is quickly fixed, for example, when the temperature of the discharge yarn is lowered in the dry part and gelled or solidified, cold air can be blown in the dry part to promote gelation. Further, although the detailed mechanism is not clear, increasing the cooling air speed to increase the cooling efficiency can increase the hole area ratio on the yarn surface and the hole diameter near the yarn outer periphery.

  As described above, the spinning solution discharged from the die is coagulated in a coagulation bath. The coagulation bath is usually composed of a coagulant such as water or alcohol or a mixture with a solvent constituting the spinning solution. Usually, water is often used. Moreover, the pore diameter can be changed by controlling the temperature of the coagulation bath. Since the pore diameter can be affected by the type of spinning dope, etc., the temperature of the coagulation bath is also appropriately selected. In general, the pore diameter can be increased by increasing the coagulation bath temperature. Although this mechanism is not exactly clear, it is thought that the solvent removal from the undiluted solution and coagulation shrinkage cause fast desolvation in the high-temperature bath and coagulation and fixation before the fiber shrinks. It is done. However, if the coagulation bath temperature becomes too high, the pore diameter becomes excessive, so that the influence such as a decrease in the pore specific surface area, a decrease in the strength and elongation, and an increase in nonspecific adsorption can be considered. Therefore, for example, when the fiber contains PMMA, the coagulation bath temperature is preferably 90 ° C. or less, more preferably 75 ° C. or less, and particularly preferably 65 ° C. or less. On the other hand, if it is too low, the pore size is reduced and the protein is less likely to diffuse into the pores. Therefore, the lower limit is preferably 12 ° C. or higher, and more preferably 20 ° C. or higher.

  Next, a step of washing the solvent adhering to the solidified fiber is passed. The means for washing the fibers is not particularly limited, but a method of allowing the fibers to pass through a multi-staged water bath (referred to as a washing bath) is preferably used. What is necessary is just to determine the temperature of the water in a washing bath according to the property of the polymer which comprises a fiber. For example, in the case of a fiber containing PMMA, 30 to 50 ° C. is adopted.

  Moreover, in order to maintain the pore diameter after the washing bath, a step of imparting a moisturizing component to the fibers may be added. The moisturizing component here refers to a component capable of maintaining the humidity of the fiber or a component capable of preventing a decrease in the humidity of the fiber in the air. Typical examples of moisturizing ingredients include glycerin and its aqueous solutions.

  After completion of washing with water and applying a moisturizing component, it is possible to pass through a bath (referred to as a heat treatment bath) filled with a heated aqueous solution of the moisturizing component in order to increase the dimensional stability of highly shrinkable fibers. The heat treatment bath is filled with an aqueous solution of a heated moisturizing component, and when the fiber passes through the heat treatment bath, the fiber is subjected to a thermal action and shrinks. It can be stabilized. The heat treatment temperature at this time varies depending on the fiber material, but in the case of a yarn containing PMMA, it is preferably 50 ° C. or higher, more preferably 80 ° C. or higher. Moreover, 95 degrees C or less is preferable and 87 degrees C or less is set as a more preferable temperature.

  As described above, the spun yarn can be wound with a fray to form a fiber material. The casket has a polygonal shape such as a hexagon and becomes a straight fiber material with little yarn disturbance.

<Preparation of purification column>
An example of means for forming a purification column using the obtained fiber material is as follows.

  First, the fiber material is cut to a required length, and the fiber material is placed in a plastic casing, which is a cylindrical portion of the purification column, so as to have a straight shape in the case axial direction. Thereafter, both ends of the fiber material are cut with a cutter or the like so that the fiber material fits in the casing, and a mesh filter cut to the same diameter as the inner diameter is attached to the outflow inlet of the liquid to be treated on both side end faces of the column. Finally, a purification column can be obtained by attaching an inlet port and an outlet port of the liquid to be treated, called header caps, at both ends of the casing.

  Moreover, when using as a medical instrument etc., ie, a medical adsorption column, it is preferable to sterilize or sterilize and use. Examples of the sterilization and sterilization methods include various sterilization / sterilization methods such as high-pressure steam sterilization, gamma ray sterilization, electron beam sterilization, ethylene oxide gas sterilization, drug sterilization, and ultraviolet sterilization. Among these methods, gamma sterilization, electron beam sterilization, high-pressure steam sterilization, and ethylene oxide gas sterilization are preferable because they have little influence on sterilization efficiency and materials.

  In addition, for all items defined in the numerical ranges described above in this specification, any numerical value such as an upper limit, a preferable upper limit, a more preferable upper limit, etc., and a lower limit, a preferable lower limit, a more preferable lower limit, etc. in each item. Any numerical range in combination with any numerical value may be used.

[Example 1]
<Production of fiber material>
31.7 parts by mass of syndiotactic PMMA (hereinafter referred to as syn-PMMA) having a mass average molecular weight of 400,000, 31.7 parts by mass of syn-PMMA having a mass average molecular weight of 1,400,000, and an isoform having a mass average molecular weight of 500,000 16.7 parts by mass of tactic PMMA (hereinafter referred to as iso-PMMA), 20 parts by mass of a PMMA copolymer having a molecular weight of 300,000 containing 1.5 mol% of parastyrene sulfonic acid soda and 376 parts by mass of dimethyl sulfoxide, The mixture was stirred at 0 ° C. for 8 hours to prepare a spinning dope. The resulting spinning dope had a viscosity at 110 ° C. of 1,240 poise. A base having a shape shown in FIG. 5 which is kept at 92 ° C. and having a discharge port having the dimensions shown in Table 1 and a base having a circular discharge port of 0.3φ are arranged at a ratio of 2: 1. The spinning dope was passed through each die at a speed of 1.1 g / min and discharged into the air, and the air part was allowed to travel 500 mm, then led to a coagulation bath and passed through the bath to obtain a solid yarn. . Water was used for the coagulation bath, and the water temperature (coagulation bath temperature) was 42 ° C. After each fiber was washed with water, led to a bath composed of an aqueous solution containing 70% by mass of glycerin as a moisturizing agent, passed through a heat treatment bath at a temperature of 84 ° C., and after removing excess glycerin, 6 m at 16 m / min. 120,000 pieces were wound with a square casserole to obtain a fiber material which is a mixed fiber bundle of fibers (max) and fibers (min).

  With respect to the obtained yarn, the degree of surface area increase, the degree of deformation, the circumscribed circle occupancy, the pore specific surface area, the equivalent circle diameter, and the like were measured by the method described above. The results are shown in Tables 1-4.

<Production of column>
The obtained fiber material was incorporated in a straight shape in a polycarbonate cylindrical casing having an inner diameter of 10 mm and an axial length of 18 mm so that the fiber filling rate was 57%. Next, a polypropylene mesh filter having an aperture equivalent diameter of 84 μm and an aperture ratio of 36%, which was cut to the same diameter as the casing inner diameter, was attached to the outlet of the liquid to be treated on both side end faces of the casing. Finally, a cap called a header having an inlet and an outlet for the liquid to be treated was attached to the casing end.

<Measurement of surface area increase degree, profile degree, circumscribed circle occupancy, and equivalent circle diameter of fiber cross section>
As described above, the fiber to be measured was cut at random positions, and the cut surface was magnified with DIGITAL MICROSCOPE DG-2 manufactured by SCARA, and photographed. At the time of photographing, a scale was also photographed at the same magnification using SCARA Co., Ltd. image analysis software “Micro Measurement ver. 1.04” and measured and calculated as described above to determine the degree of surface area increase and the degree of deformity.

<Measurement of adsorption performance of fiber material>
Within 5 days after blood collection, the bovine blood to which sodium azide was added was adjusted so that the hematocrit was 30 ± 3% and the total protein amount was 6.5 ± 0.5 g / dL. Next, it added and stirred so that (beta) _2- MG density | concentration might be 1 mg / L. Further, the length of the fiber material was adjusted so that the fiber material contained approximately 100 fibers and the volume of the fibers was 0.0905 cm ³ , and the fiber material was placed in, for example, a 15 mL centrifuge tube manufactured by Greiner. 12 mL of the above bovine plasma is put therein, and using a Wave-SI manufactured by TAITEC, for example, a seesaw shaker, the scale is set to 38 and the angle is maximum (one reciprocation in 1.7 seconds), and at room temperature (20 to 25 ° C.). Stir for 1 hour. In order to measure β ₂ -MG concentration C ₁ (mg / mL) before stirring and β ₂ -MG concentration C ₂ (mg / mL) after stirring, 1 mL each was sampled and stored in a freezer at −20 ° C. or lower. saved. The β ₂ -MG concentration was measured by the latex agglomeration method, and the adsorption amount per fiber volume was calculated from the following equation (12).
Adsorption amount per fiber volume (mg / cm ³ ) = (C ₁ -C ₂ ) × 12 / 0.0905 (12)
<Measurement of column adsorption performance>
For evaluating the adsorption performance of the column, the clearance of β ₂ -MG was measured. Plasma was obtained from bovine blood supplemented with sodium azide by centrifugation. The plasma was adjusted so that the hematocrit was 30 ± 3% and the total protein amount was 6.5 ± 0.5 g / dL. In addition, bovine plasma was used within 5 days after blood collection. Next, it added and stirred so that (beta) _2- MG density | concentration in bovine plasma might be set to 1 mg / L. The bovine plasma was divided into 35 mL for circulation and 40 mL for clearance measurement.

  The circuit was set as shown in FIG. In the circuit, Bi was taken as the inlet for taking up the liquid to be treated, and Bo as the liquid outlet after the purification column was passed through.

  Put Bi into the circulating beaker containing 35 mL (37 ° C) of bovine plasma adjusted as above, start the pump at a flow rate of 3.5 mL / min, and discard the first 90 seconds of liquid drained from Bo Immediately, Bo was placed in a beaker for circulation to obtain a circulation state. After 1 hour of circulation, the pump was stopped.

  Next, Bi was put in the bovine plasma for clearance measurement adjusted as described above, and Bo was put in a waste beaker.

  The flow rate was 3.5 mL / min, and after 2 minutes from the start of the pump, 1 mL of a sample was collected from bovine plasma (37 ° C.) for clearance measurement and used as Bi solution. After 4 minutes and 30 seconds from the start, 1 mL of a sample that flowed from Bo was collected and used as Bo solution. These samples were stored in a freezer at -20 ° C or lower.

The clearance was calculated from the β ₂ -MG concentration of each solution by the following equation (13). Since measured values may differ depending on the lot of bovine blood, bovine plasma of the same lot was used for all of the examples and comparative examples.
Co (mL / min) = (CBi−CBo) × Q _B / CBi (13)
In the above equation _{(13), C O = β} 2 -MG Clearance (mL / min), CBi = β 2 -MG concentration in Bi liquid, beta ₂ -MG concentration in CBO = Bo _liquid, Q B = Bi pump flow ( mL / min). In order to obtain the adsorption performance per surface area, Ko was calculated from the following equation (14).
Ko (cm / min) = Q _B / A × ln [Q _B / (Q _B −Co)] (14)
In the above equation (14), Ko = β ₂ -MG is an overall mass transfer coefficient (cm / min), and A is the total fiber surface area (cm ² ) of the fiber material.
The results are shown in Table 4.

[Examples 2 to 5]
A fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and size shown in Table 1 and the base having the discharge port having the shape and size shown in Table 2 were arranged at 2: 1. Was made. The results are shown in Tables 3 and 4.

[Example 6]
The fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and size shown in Table 1 and the base having the discharge port having the shape and size shown in Table 2 were arranged at 1: 2. Was made. The results are shown in Tables 3 and 4.

[Example 7]
A fiber material / column under the same conditions as in Example 1 except that a base having a discharge port having the shape and dimensions shown in Table 1 and a base having a discharge port having the shape and dimensions shown in Table 2 are arranged at 1: 1. Was made. The results are shown in Tables 3 and 4.

[Example 8]
Example 1 except that the base having the discharge port having the shape and size shown in Table 1 and the base having the discharge port having the shape and size shown in Table 2 are arranged at 2.5: 1 (= 5: 2). A fiber material / column was prepared under the same conditions. The results are shown in Tables 3 and 4.

[Example 9]
A fiber material / column under the same conditions as in Example 1 except that a base having a discharge port having the shape and dimensions shown in Table 1 and a base having a discharge port having the shape and dimensions shown in Table 2 are arranged at 3: 1. Was made. The results are shown in Tables 3 and 4.

[Example 10]
A fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and dimensions shown in Table 1 and the base having the discharge port having the shape and dimensions shown in Table 2 are arranged at 5: 1. Was made. The results are shown in Tables 3 and 4.

[Example 11]
The fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and size shown in Table 1 and the base having the discharge port having the shape and size shown in Table 2 were arranged at 8: 1. Was made. The results are shown in Tables 3 and 4.

[Example 12]
The fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and size shown in Table 1 and the base having the discharge port having the shape and size shown in Table 2 were arranged at 10: 1. Was made. The results are shown in Tables 3 and 4.

[Example 13]
A base having a discharge port having the shape and size shown in Table 1 and a base having a discharge port having the shape and size shown in Table 2 are arranged at 2: 1, and the discharge amount is 1.1 g / min: 0.41 g / min. A fiber material / column was prepared under the same conditions as in Example 1 except that. The results are shown in Tables 3 and 4.

[Example 14]
A base having a discharge port having the shape and dimensions shown in Table 1 and a base having a discharge port having the shape and dimensions shown in Table 2 are arranged in a ratio of 2: 1, and the discharge amount is 1.1 g / min: 0.72 g / min. A fiber material / column was prepared under the same conditions as in Example 1 except that. The results are shown in Tables 3 and 4.

[Example 15]
A base having a discharge port having the dimensions shown in Table 1 and a base having a discharge port having the dimensions shown in Table 2 were arranged at 2: 1, and the discharge amount was 1.1 g / min: 1.30 g / min. A fiber material / column was prepared under the same conditions as in Example 1. The results are shown in Tables 3 and 4.

[Example 16]
A base having a discharge port having the shape and size shown in Table 1 and a base having a discharge port having the shape and size shown in Table 2 are arranged at a ratio of 2: 1, and the discharge amount is 1.1 g / min: 1.90 g / min. A fiber material / column was prepared under the same conditions as in Example 1 except that. The results are shown in Tables 3 and 4.

[Example 17]
A base having a discharge port having the shape and dimensions shown in Table 1 and a base having a discharge port having the shape and dimensions shown in Table 2 are arranged at a ratio of 2: 1, and the discharge amount is 1.1 g / min: 5.00 g / min. A fiber material / column was prepared under the same conditions as in Example 1 except that. The results are shown in Tables 3 and 4.

[Examples 18 to 21]
A fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and dimensions shown in Table 1 and the base having the shape and discharge port having the dimensions shown in Table 2 are arranged at 2: 1. Was made. The results are shown in Tables 3 and 4.

[Comparative Example 1]
A fiber material / column was produced under the same conditions as in Example 1 except that only a die having a discharge port having the shape and dimensions shown in Table 1 was arranged. The results are shown in Tables 3 and 4.

[Comparative Example 2]
A fiber material / column was produced under the same conditions as in Example 1 except that only a die having a discharge port having the shape and dimensions shown in Table 1 was arranged. The results are shown in Tables 3 and 4.

[Comparative Example 3]
A fiber material / column was produced under the same conditions as in Example 1 except that only a base having a circular discharge port was disposed. The results are shown in Tables 3 and 4.

[Comparative Example 4]
The fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and dimensions shown in Table 1 and the base having the discharge port having the shape and dimensions shown in Table 2 were arranged at 1: 5. Was made. The results are shown in Tables 3 and 4.

[Comparative Example 5]
A fiber material / column under the same conditions as in Example 1 except that the base having the discharge port having the shape and size shown in Table 1 and the base having the discharge port having the shape and size shown in Table 2 were arranged at 24: 1. Was made. The results are shown in Tables 3 and 4.

[Comparative Example 6]
A fiber material / column was prepared under the same conditions as in Example 1 except that a commercially available nylon Tegus (No. 0.5 manufactured by Fujino) was used as the adsorbing material. The results are shown in Tables 3 and 4.

  From the results of Examples 1 to 5 and Comparative Examples 1 to 3, it is a cross thread and a fiber (min) which are fibers (max) compared to a column made of a single fiber such as a cross thread, an elliptical thread, and a circular thread. It can be seen that the adsorption performance Co of the column of the mixed fiber material with the elliptical thread or the circular thread is high. Further, the fiber (min) tended to have a higher Ko indicating the adsorption performance per surface area as the degree of deformity increased and the circumscribed circle occupancy decreased. From this, when the cross section of the fiber (min) is circular or elliptical, the amount of surface area as the fiber material is increased by increasing the degree of surface area increase, the degree of irregularity is high, and the degree of circumscribed circle occupancy is lower It is considered that the effect of suppressing fiber adhesion due to mixed fibers is increased.

  From the results of Examples 3 and 6 to 12 and Comparative Examples 4 and 5, Comparative Example 1 in which the cruciform alone was used under the condition that the blend ratio (fiber (max): fiber (min)) was 1: 2 to 10: 1. And Co and Ko tended to be higher than those of Comparative Example 2 in which the elliptical thread alone was used. On the other hand, in Comparative Example 4, the ratio of the fiber (max) is as low as 17%. In this case, Co has a lower value than Comparative Example 1 used alone as a cross yarn, and Ko is a comparative example. It was almost equivalent to 1-3. This is presumably because the effect of increasing the surface area by the fibers (max) was insufficient and the fibers (min) were in close contact with each other, and the surface area could not be fully utilized. In Comparative Example 5, since the yarn adhesion suppressing effect was insufficient under the low fiber (min) ratio of 4%, Ko was as low as that of the elliptical yarn of Comparative Example 1 alone. It was not obtained.

From the results of Examples 3 and 13 to 17, it can be seen that if the equivalent-circle diameter of the fiber (min) is too large compared to the fiber (max), the loss of the surface area increases and the adsorption performance tends to decrease.
Examples 3, 18 and 19 show that the adsorption performance is improved by increasing the circumscribed circle occupancy of the fiber (max). By increasing the circumscribed circle occupancy of the fiber (max), there is less overlap between the fibers, such as the adjacent fibers entering the valleys of the protrusions of the fiber (max), and the effect of suppressing the adhesion between the yarns has increased. It is considered a thing.

  As a result of changing the yarn cross-sectional shape of the fiber (min) in Examples 3, 20 and 21, the performance of the fiber (min) in the Y shape is higher than that of the star shape, and the elliptical shape is more than the Y shape. It can be seen that Co and Ko are higher. From this, it is considered that a fiber (min) having a higher degree of irregularity and a lower circumscribed circle occupation is more advantageous. This is thought to be due to the fact that the yarn adhesion suppression effect by the fibers (min) is increased by reducing the circumscribed circle occupancy.

  Further, from the results of Example 3 and Comparative Example 6, the porous fiber material used in the Examples has high adsorption performance per fiber volume and sufficient protein adsorption compared to the yarn having a low specific surface area as in Comparative Example 6. It can be seen that it has the ability.

[Example 22]
<Production of column>
Using the same yarn as in Example 3, 50,000 fibers (max) and 25,000 fibers (min) were placed in a polycarbonate cylindrical casing having an inner diameter of 46 mm and an axial length of 140 mm. It was built in a straight shape so that the filling rate was 57%. Next, a polypropylene mesh filter having an aperture equivalent diameter of 84 μm and an aperture ratio of 36%, which was cut to the same diameter as the casing inner diameter, was attached to the outlet of the liquid to be treated on both side end faces of the casing. Finally, a cap called a header having an inlet and an outlet for the liquid to be treated was attached to the casing end. The equivalent circle diameter, surface area increase degree, and average pore radius of the yarn were measured by the method described above. Further, with respect to the produced column, the adsorption performance, pressure loss, and residual blood volume were measured by the methods described later. The results are shown in Table 5.

<Measurement of column adsorption performance>
For evaluating the adsorption performance, the clearance of β ₂ -MG was measured. The bovine blood to which disodium ethylenediaminetetraacetate was added was adjusted so that the hematocrit was 30 ± 3% and the total protein amount was 6.5 ± 0.5 g / dL. The bovine blood used within 5 days after blood collection.

Next, it added and stirred so that (beta) _2- MG density | concentration might be 1 mg / L. The cow blood was divided into 2 L for circulation and 1.5 L for clearance measurement.

  The circuit was set as shown in FIG. In the circuit, Bi was taken as the inlet for taking up the liquid to be treated, and Bo as the liquid outlet after the purification column was passed through.

  Put Bi in the circulating beaker containing 2 L of cattle blood (37 ° C) prepared above, start the pump at a flow rate of 200 mL / min, and immediately discard the 90 seconds of liquid drained from Bo immediately. Bo was put in a beaker for circulation to obtain a circulation state. After 1 hour of circulation, the pump was stopped.

  Next, Bi was put into the bovine blood for clearance measurement adjusted as described above, and Bo was put into a waste beaker.

  The flow rate was 200 mL / min, and after 2 minutes from the start of the pump, 10 mL of a sample was collected from cow blood (37 ° C.) for clearance measurement, and used as Bi solution. After 4 minutes and 30 seconds from the start, 10 mL of the sample that flowed from Bo was collected and used as Bo solution. These samples were stored in a freezer at -20 ° C or lower.

The clearance Co was calculated from the concentration of β ₂ -MG in each solution. Since measured values may differ depending on the lot of bovine blood, bovine blood of the same lot was used in all of the examples and comparative examples.

  The results are shown in Table 5.

<Measurement of pressure loss in bovine blood>
In the above-described adsorption performance measurement of the column, the pressure of Bi and Bo was measured 5 minutes after the start of clearance measurement, and the pressure difference between Bi and Bo was taken as the pressure loss. The results are shown in Table 5.

[Comparative Example 7]
A column was prepared and evaluated in the same manner as in Example 22 except that the same yarn as in Comparative Example 1 was used and the number of yarns was changed to 75,000. The results are shown in Table 5.

[Comparative Example 8]
A column was prepared and evaluated in the same manner as in Example 22 except that the same yarn as in Comparative Example 2 was used and the number of yarns was changed to 75,000. The results are shown in Table 5.

As described above, from the results of Example 22 and Comparative Examples 7 and 8, the cruciform yarn and the fiber (min), which are fibers (max), also in the column, compared to the column made of a single fiber of cruciform yarn or elliptic yarn. It can be seen that the β ₂ -MG clearance of the elliptical yarn is high.

  In addition, the macro void was not confirmed by all the fibers used by the Example of this patent, the comparative example, and the reference example.

  Since the fiber material of the present invention efficiently adsorbs and removes the substance to be adsorbed in the liquid to be treated, it can be used in a purification column. The specific use of the purification column is diverse, and can be used for various purposes such as water treatment, purification, and medical treatment.

1 circumscribed circle 2 inscribed circle 3 circumscribed circle diameter Do
4 Inscribed circle diameter Di
DESCRIPTION OF SYMBOLS 10 Slit part length 11 Slit part width R Arc W Slit part width L Slit part length 13 Purification column 14 Pump 15 37 degreeC hot water bath 16 Disposal beaker 17 Circulating plasma 18 Clearance measuring plasma

Claims (20)

Including a mixed fiber having a plurality of solid fibers having a common cross-sectional shape, and at least two of the plurality of types of fibers have a composition ratio of 5.0% or more in the entire mixed fiber, Of the plurality of types of fibers having a composition ratio of 5.0% or more, the fiber having the highest surface area increase degree represented by the following formula (1) is the fiber (max), and the surface area represented by the following formula (1). When the fiber having the lowest degree of increase is defined as fiber (min), the fiber (min) has a surface area increase of 3.0% or more lower than that of the fiber (max), and the fiber (max) of the mixed fiber. The composition ratio in the whole is 30.0% or more, the composition ratio in the whole of the mixed fiber of the fiber (min) is 8.0% or more, and the fiber (max) has (a) surface area increase degree of 1. 20 or more, (b) porous and a pore specific surface area of 5 A fiber material that is at least m ² / g.
Increase in surface area = (perimeter in fiber cross section) / (circumference length in a circle having the same cross-sectional area as the fiber cross section) (1) The fiber material according to claim 1, wherein the pore specific surface area of the fiber (max) is 10 m ² / g or more. The fiber material according to claim 1 or 2, wherein the fiber (min) is porous and has a pore specific surface area of 5 m ² / g or more. The fiber material according to claim 3, wherein the pore specific surface area is 10 m ² / g or more. The circumscribed circle occupation degree Sfo represented by the following formula (2) in the fiber (min) is 0.90 or less, The fiber material according to any one of claims 1 to 4.
Circumscribed circle occupancy Sfo = Sf / So (2)
Here, Sf: cross-sectional area of the fiber cross section, So: area surrounded by a circumscribed circle of the fiber cross section. The fiber material according to any one of claims 1 to 5, wherein a degree of deformation Do / Di in the fiber (min) is 1.10 or more.
Here, Do: the diameter of the circumscribed circle of the fiber cross section, Di: the diameter of the inscribed circle of the fiber cross section.   The fiber material according to any one of claims 1 to 6, wherein a degree of surface area increase of the fiber (min) is 1.10 or more.   The fiber material according to any one of claims 1 to 7, wherein a shape of a fiber cross section of the fiber (min) is a circle or an ellipse.   The fiber material according to any one of claims 1 to 8, wherein an equivalent circle diameter of the fiber (max) is 10 µm or more and 1,000 µm or less.   The fiber material according to any one of claims 1 to 9, wherein an Sfo ratio Z obtained by dividing a circumscribed circle occupancy Sfo of the fiber (min) by a circumscribed circle occupancy Sfo of the fiber (max) is 0.20 or more. .   The fiber diameter ratio Y represented by dividing the equivalent circle diameter of the fiber (max) by the equivalent circle diameter of the fiber (min) is 10.0 or less. Fiber material.   The fiber material according to any one of claims 1 to 11, comprising straight-shaped fibers.   The fiber material as described in any one of Claims 1-12 which the said mixed fiber consists of a fiber which makes two types of cross-sectional shape common.   The fiber material according to any one of claims 1 to 13, wherein a ratio of the fiber (max) to the fiber (min) is 10: 1 to 1: 2.   The fiber material according to any one of claims 1 to 14, wherein the fiber (max) and the fiber (min) are formed of the same material.   The fiber material according to claim 15, wherein the material is an ester group-containing polymer.   The fiber material as described in any one of Claims 1-16 used for a medical use.   The fiber material according to any one of claims 1 to 17, which is used for a purification column. The fiber material according to claim 1, wherein the adsorption amount of β ₂ -microglobulin is 0.005 mg / cm ³ or more.   A purification column comprising a plastic casing and the fiber material according to any one of claims 1 to 19, wherein the fiber material has a straight shape in an axial direction connecting both side openings of the case in the plastic casing. A purification column which is arranged and has an inlet port and an outlet port for a liquid to be treated attached to both ends of the plastic casing.