Hollow fiber membrane module and method for manufacturing same

Abstract

The purpose of the present invention is to provide a hollow fiber membrane module for virus removal which is resistant to high pressure and high heat, and to provide a method for manufacturing the same. A hollow fiber membrane module 1 comprises: a tubular container 2 in which a hollow fiber membrane bundle 3 is accommodated; and headers 5 which are provided at both end portions of the tubular container 2 with each header 5 having a fluid inlet / outlet 5a. Each end portion of the tubular container 2 is welded to an end portion of the header 5 over the entire circumference in the circumferential direction. The tubular container 2 and the headers 5 are formed from an amorphous polymer having a transmittance of 10% or more and a heat deflection temperature of 130°C or more. The welding width W at a welded portion 9 between the tubular container 2 and each header 5 is not less than 1 / 211 of the inner diameter of the tubular container 2.

Description

Hollow fiber membrane module and manufacturing method thereof

[0001] The present invention relates to a hollow fiber membrane module and a method for producing the same.

[0002] Conventionally, hollow fiber membrane modules have been used as blood purifiers or component separators in extracorporeal blood purification treatments (hemodialysis, hemodiafiltration, hemofiltration, plasma separation, etc.), treatment of body cavity fluids such as ascites, and virus removal treatments for protein-containing preparations (plasma fraction preparations, biopharmaceuticals, etc.).

[0003] A hollow fiber membrane module generally includes a cylindrical container that houses a hollow fiber membrane bundle therein and has two ports (an inlet port and an outlet port) on its side for fluid inlet and outlet, and headers that are provided at both ends of the cylindrical container and have fluid inlet and outlet ports. Currently, hollow fiber membrane modules in which the header and the cylindrical container are welded by ultrasonic welding (see, for example, Patent Documents 1 and 2), and hollow fiber membrane modules in which the header and the cylindrical container are joined by a screw portion (see, for example, Patent Documents 3 and 4) are known.

[0004] The fluid inlet and outlet of the header of such a hollow fiber membrane module communicates with the inner region of each hollow fiber membrane, and the ports on the side of the tubular container communicate with the outer region of each hollow fiber membrane. For example, in virus removal using a hollow fiber membrane module, a virus-containing protein solution is pressurized and supplied to the fluid inlet of the header using a pump or gas, the supplied liquid is filtered from the inside of the hollow fibers through the membrane pores, and the protein preparation smaller than the membrane pore size is recovered from the port on the side of the module and separated from viruses larger than the membrane pore size.

[0005] International Publication No. 2003 / 146663 International Publication No. 2017 / 171015 Chinese Utility Model No. ZL202122628115.3 Japanese Patent Application Laid-Open No. 2013-208608

[0006] Since hollow fiber membrane modules used for virus removal from protein-containing preparations require high sterility, they are generally subjected to cleaning with chemicals such as alkali (Cleaning in Place: CIP) and / or sterilization with saturated steam (SIP: Sterilization in Place) before use after being incorporated into a pharmaceutical production line. Therefore, hollow fiber membrane modules used for virus removal are required to be resistant to chemicals and / or high heat, and in recent years, attempts have been made to prepare headers and cylindrical containers from resins that are resistant to high heat. In particular, in order to kill heat-resistant spore-forming bacteria (Clothria botulinum), it is desirable for the hollow fiber membrane modules to be resistant to high heat of 130°C or higher.

[0007] However, it is generally difficult to control the dimensions of high-heat-resistant resins during injection molding. Therefore, when a hollow fiber membrane module is formed by joining a header made of a material containing a high-heat-resistant resin to a cylindrical container, dimensional variations are likely to cause problems in the joining of the header and the cylindrical container, leading to concerns about loss of liquid-tightness, separation of the header from the cylindrical container under high-pressure and high-heat conditions, or partial damage to the welded portion between the header and the cylindrical container. Biopharmaceuticals, which have seen increasing demand in recent years as protein-containing formulations, require the virus removal process to process a large amount of solution in a short period of time, so a high-pressure virus removal process is carried out. However, liquid leakage from the header can easily become a problem during this process.

[0008] In particular, when attempting to weld a header made of a material containing a highly heat-resistant resin to a cylindrical container by ultrasonic welding as described in Patent Documents 1 and 2, high-energy ultrasonic vibrations must be applied to melt the resin, making it difficult to apply. Furthermore, with highly heat-resistant resins, it is difficult to control the dimensions during injection molding, making it difficult to adopt the methods described in Patent Documents 3 and 4, which require thread machining.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hollow fiber membrane module that is resistant to high pressure and high heat, and to provide a method for producing the same.

[0010] The present invention includes the following aspects: <1> A hollow fiber membrane module comprising a cylindrical container that houses a hollow fiber membrane bundle and headers that are provided at both ends of the cylindrical container and have inlets and outlets for fluids, wherein each end of the cylindrical container is welded to an end of the header along the entire circumferential direction, the cylindrical container and the header are made of an amorphous polymer that has a permeability of 10% or more and a deflection temperature under load of 130°C or more, and the weld width at the welded portion between the cylindrical container and the header is 1 / 211 or more of the inner diameter of the cylindrical container. <2> The hollow fiber membrane module according to <1>, wherein the inner diameter of the cylindrical container is set to 20 to 200 mm. <3> The hollow fiber membrane module according to <1> or <2>, further comprising potting sections at both ends of the cylindrical container to embed and fix the hollow fiber membrane bundle, wherein a convex section protruding toward the header is provided in the central region of both ends of the potting section, thereby forming a concave section between the end of the cylindrical container forming the welded section and the convex section of the potting section. <4> The hollow fiber membrane module according to <3>, wherein both ends of the convex section have cut surfaces formed by cutting the convex section in the radial direction, and the side surfaces of the convex sections are inclined at an angle of 90 to 130° with respect to the cut surfaces in a side view. <5> The hollow fiber membrane module according to any one of <1> to <4>, wherein the cylindrical container has a nozzle serving as an inlet / outlet for a fluid, and wherein the inner diameter of the nozzle is 6.0 mm or more. <6> The hollow fiber membrane module according to any one of <1> to <5>, wherein the cylindrical container has a uniform thickness. <7> The hollow fiber membrane module according to any one of <1> to <6>, wherein the thickness of the cylindrical container is 1.0 mm or more and less than 15 mm. <8> The hollow fiber membrane module according to any one of <1> to <7>, wherein each end of the cylindrical container is welded to the end of the header uniformly over the entire circumferential direction of the cylindrical container. <9> The hollow fiber membrane module according to any one of <1> to <8>, wherein the tensile strength of the welded portion is 95% or more of the tensile strength of the amorphous polymer constituting the cylindrical container and the header.<10> The hollow fiber membrane module according to any one of <1> to <9>, wherein the amorphous polymer is polyphenylsulfone (PPSU) or polysulfone (PSU). <11> The hollow fiber membrane module according to any one of <1> to <10>, wherein the cylindrical container is a cylinder. <12> The hollow fiber membrane module according to any one of <1> to <11>, which is used for virus removal. <13> A hollow fiber membrane module comprising a cylindrical container that houses a hollow fiber membrane bundle and headers that are provided at both ends of the cylindrical container and have inlets and outlets for fluids, wherein each end of the cylindrical container is welded to an end of the header along the entire circumferential direction, the cylindrical container and the header are made of an amorphous polymer having a permeability of 10% or more and a deflection temperature under load of 130°C or more, and the tensile strength at the welded portion is 80% or more of the tensile strength of the amorphous polymer that constitutes the cylindrical container and the header. <14> The hollow fiber membrane module according to <13>, wherein the weld width at the welded portion between the cylindrical container and the header is 1 / 169 or more of the inner diameter of the cylindrical container. <15> A method for producing a hollow fiber membrane module comprising a cylindrical container and headers provided at both ends of the cylindrical container, the method comprising a welding step of welding each end of the cylindrical container to an end of the header by infrared radiation, wherein the cylindrical container and the header are made of an amorphous polymer having a transmittance of 10% or more and a deflection temperature under load of 130°C or more. <16> The method according to <15>, wherein in the welding step, a weld width at the welded portion between the cylindrical container and the header is set to 1 / 211 or more of the inner diameter of the cylindrical container. <17> The method according to <15> or <16>, wherein the inner diameter of the cylindrical container is 20 to 200 mm. <18> The method according to any one of <15> to <17>, further comprising a drying step of drying the cylindrical container and the header before the infrared radiation. <19> The production method according to any one of <15> to <18>, further comprising a step of filling the cylindrical container with a hollow fiber membrane bundle before the infrared irradiation.<20> The manufacturing method according to any one of <15> to <19>, wherein the welding step includes a pressurizing and holding step of pressing the end of the cylindrical container and the end of the header together under infrared irradiation. <21> The manufacturing method according to any one of <15> to <20>, wherein the tensile strength of the welded portion between the cylindrical container and the header is 95% or more of the tensile strength of the amorphous polymer constituting the cylindrical container and the header. <22> The manufacturing method according to any one of <15> to <21>, further including a high-pressure steam sterilization step at 130°C or higher. <23> The manufacturing method according to any one of <15> to <22>, wherein the amorphous polymer is polyphenylsulfone (PPSU) or polysulfone (PSU).

[0011] According to the present invention, it is possible to provide a hollow fiber membrane module that is resistant to high pressure and high heat, and to provide a method for producing the same.

[0012] 1 is a longitudinal sectional view illustrating the configuration of a hollow fiber membrane module according to an embodiment of the present invention; FIG. 2 is an enlarged sectional view of part II (end of the cylindrical container) in FIG. 1; FIG. 3 is an enlarged sectional view of part III (end of the header) in FIG. 1; FIG. 4 shows a welded portion of a hollow fiber membrane module in Example 3, where (a) is an X-ray CT image of a cross section of the welded portion taken along the axial direction of the cylindrical container, and (b) is an X-ray CT image of the welded portion viewed from above; and FIG. 5 shows a welded portion of a hollow fiber membrane module in a comparative example, where (a) is an X-ray CT image of a cross section of the welded portion taken along the axial direction of the cylindrical container, and (b) is an X-ray CT image of the welded portion viewed from above.

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same elements are given the same reference numerals, and redundant explanations will be omitted. Furthermore, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to the illustrated ratios. Furthermore, the following embodiments are examples for explaining the present invention, and the present invention is not limited to these embodiments.

[0014] First, the configuration of a hollow fiber membrane module 1 according to an embodiment of the present invention will be described. Fig. 1 is a schematic longitudinal cross-sectional view of the hollow fiber membrane module 1 according to this embodiment, taken along a plane passing through its central axis P. The hollow fiber membrane module 1 according to this embodiment comprises a cylindrical container 2, a hollow fiber membrane bundle 3, a potting section 4, a header 5, etc. The hollow fiber membrane module 1 according to this embodiment is used, for example, for virus removal, and preferably has a pressure resistance of 0.3 MPa or more, more preferably 0.6 MPa or more, or 1.0 MPa or more.

[0015] The cylindrical container 2 is formed in a cylindrical shape and has at least one end 2a in the longitudinal direction (direction of the central axis P of the cylinder) open (in this embodiment, both ends are open). A hollow fiber membrane bundle 3 is housed inside the cylindrical container 2. Two nozzles 6 (only one nozzle 6 is shown in FIG. 1 ) are formed on the side of the cylindrical container 2, serving as fluid inlets and outlets. The inner diameter of the nozzle 6 can be set to, for example, 6.0 mm or more, 6.7 mm or more, or 8.9 mm or more. The inner diameter of the nozzle 6 can be set to, for example, 50 mm or less, 40 mm or less, or 30 mm or less. The lower limit of the inner diameter of the cylindrical container 2 can be set to, for example, 20 mm or more, 35 mm or more, or 55 mm or more. The upper limit of the inner diameter of the cylindrical container 2 can be set to, for example, 200 mm or less, 140 mm or less, or 100 mm or less. The inner diameter of the cylindrical container 2 can be set within a range of, for example, 20 mm to 200 mm, 35 mm to 200 mm, 55 mm to 200 mm, 20 mm to 140 mm, 35 mm to 140 mm, 55 mm to 140 mm, or 35 mm to 100 mm. The thickness T of the wall 2b constituting the cylindrical container 2 can be set appropriately depending on the size of the cylindrical container 2 (for example, a lower limit of 0.5 mm or more, 1.0 mm or more, or 2.0 mm or more, an upper limit of 15 mm or less, 10.0 mm or less, or 8.0 mm or less, or a range of 0.5 mm to 20 mm or less, 1.0 mm to 10.0 mm or less, 1.0 mm to 8.0 mm or less, or 2.0 mm to 8.0 mm or less, etc.). In this case, the thickness of the wall 2b can be made uniform. Each end of the cylindrical container 2 is welded uniformly throughout its entire circumferential direction to the end 5a of the header 5 (see FIG. 3 ).

[0016] The hollow fiber membrane bundle 3 is, for example, a bundle of many hollow fiber membranes, and is housed longitudinally in a cylindrical container 2 as shown in FIG. 1 . The hollow fiber membrane bundle 3 functions as a separation membrane, and can separate components of a fluid to be separated between the inner and outer regions of each hollow fiber membrane. The material of the hollow fiber membrane is not particularly limited as long as it is a material that can remove viruses, and examples thereof include polyethersulfone, polysulfone, polyvinylidene fluoride, cellulose, regenerated cellulose, cellulose derivatives, and mixtures thereof. A "cellulose derivative" is a compound obtained by introducing different substituents into the hydroxyl groups contained in a cellulose molecule. Hollow fiber membranes made of these materials and hollow fiber membranes containing these materials can be manufactured by known methods.

[0017] The potting portion 4 is made of potting resin and, as shown in FIG. 1 , embeds both ends 3 a of the hollow fiber membrane bundle 3 inside both ends 2 a of the cylindrical container 2 and fixes the hollow fiber membrane bundle 3 to both ends 2 a of the cylindrical container 2 (at this time, excess potting resin is cut and removed to open the end faces of the hollow fiber membrane bundle 3). The potting portion 4 is formed inside the cylindrical container 2 at a position corresponding to the rib 7 formed on the outer periphery, as shown in FIG. 1 (i.e., the rib 7 of the cylindrical container 2 is formed on the outer periphery of the cylindrical container 2 at a position corresponding to the potting portion 4 formed inside the cylindrical container 2, as shown in FIG. 1). The outer peripheral regions at both ends of the potting portion 4 are portions 4 a composed only of potting resin, and the inner region (central region) is portion 4 b where the potting resin has filled the gaps between the hollow fiber membranes of the hollow fiber membrane bundle 3. Examples of potting resins include polyurethane resin, epoxy resin, and silicone resin.

[0018] 1, a convex portion 4c that protrudes toward the header 5 is provided in the central region 4b at both ends of the potting portion 4, thereby forming a concave portion 4d between the end 2a of the cylindrical container 2 that forms the welded portion 9 between the cylindrical container 2 and the header 5 and the convex portion 4c of the potting portion 4. Cut surfaces 4ca formed by cutting the convex portion 4c in the radial direction are formed at both ends of the convex portion 4c, and the side surfaces 4cb of the convex portion 4c can be inclined at an angle of, for example, 90 to 130°, 95 to 120°, or 100 to 115° with respect to the cut surface 4ca in a side view.

[0019] The headers 5 are provided as lids at the openings of both end portions 2a of the cylindrical container 2 and have fluid inlets and outlets 5b (see FIG. 1). The end portions 2a of the cylindrical container 2 (see FIG. 2) and the end portions 5a of the headers 5 (see FIG. 3) are joined by, for example, infrared welding, and are sealed to prevent liquid leakage. In this embodiment, the cylindrical container 2 and the headers 5 are made of an amorphous polymer having a transmittance of 10% or more and a deflection temperature under load of 120°C or more (preferably 130°C or more, more preferably 150°C or more). The deflection temperature under load can be determined by Method A of ISO 75-2:2013. Examples of such amorphous polymers that can be used include polyphenylsulfone (PPSU), polysulfone (PSU), polycarbonate (PC), polyethersulfone (PES), polyarylate (PAR), and polyetherimide (PEI). When performing high-temperature steam sterilization (SIP) before the virus removal step, it is particularly preferable to use polyphenylsulfone (PPSU) or polysulfone (PSU), which have excellent resistance to high pressure and high temperature, as the amorphous polymer.

[0020] The header 5 has a structure (flange) 8 that covers the rib 7. The flange 8 is configured to cover part or all of the rib 7, but a continuous cylindrical structure that covers the entire rib 7 is preferable because it has high resistance to impact. The rib 7 is formed on the outer periphery of the cylindrical container 2 at a position corresponding to the potting portion 4. The rib 7 has a convex structure relative to the outer surface of the cylindrical container 2 and is made of the same material as the cylindrical container 2. The rib 7 may have, for example, a spiral shape and may be continuous or discontinuous. The shape of the rib 7 may be, for example, a tapered shape that becomes thinner toward the outside. Various tapered shapes may also be used. For example, a rib 7 that is approximately triangular in cross section or a rib 7 that is approximately trapezoidal in cross section may be used.

[0021] The height of the rib 7 is preferably set to a value within the range of 0.5 to 4.0 mm (e.g., 0.8 mm, 2.5 mm, etc.). The height H of the rib 7 is the distance from the top of the rib 7 to the outer peripheral surface of the cylindrical container 2 (if there are multiple positions on the outer peripheral surface of the cylindrical container 2 as shown in Figures 1 and 2, the height H is the distance from the top of the rib 7 to the outer peripheral surface that is farthest from the top of the rib 7). The maximum width of the rib 7 is also preferably set to a value within the range of 0.5 to 4.0 mm (e.g., 1.4 mm, 2.5 mm, etc.). In the case of a tapered rib 7, the maximum width of the rib 7 is the width value at the base end of the rib 7.

[0022] The weld width W at the welded portion 9 between the cylindrical container 2 and the header 5 is set to 1 / 211 or more of the inner diameter of the cylindrical container 2, and is preferably set to 0.5 mm or more (1.0 mm or more, 2.0 mm or more, etc.). In this embodiment, the welded portion 9 may include burrs, but the weld width W does not include the burrs. The weld width W may be less than the thickness T of the wall 2b constituting the cylindrical container 2, but is preferably equal to the thickness T of the wall 2b. When the weld width W is set to 1 / 211 or more of the inner diameter of the cylindrical container 2, the pressure resistance of the hollow fiber membrane module 1 will be 0.6 MPa or more when the tensile strength of the amorphous polymer constituting the cylindrical container 2 and the header 5 is 70 MPa (welding efficiency 100%). The ratio of the weld width W to the inner diameter of the cylindrical container 2 has a lower limit of preferably 1 / 211 or 1 / 150 from the viewpoint of the pressure-resistant strength of the hollow fiber membrane module 1, and an upper limit of preferably 1 / 15, 1 / 30, or 1 / 60 from the viewpoint of the injection moldability of the cylindrical container 2 and the header 5, and ranges of 1 / 211 to 1 / 15, 1 / 200 to 1 / 30, or 1 / 150 to 1 / 60. The welding efficiency is a value obtained by dividing the tensile strength of the welded portion 9 by the tensile strength of the resin matrix (resin before welding) and multiplying the result by 100, and is preferably 80% or more, more preferably 90% or more, 95% or more, and even more preferably 98% or more, or 100%. When the weld width W is set to 1 / 169 or more of the inner diameter of the cylindrical container 2, a target pressure-resistant value of 0.6 MPa or more can be achieved even if the welding efficiency is 80% or more. Furthermore, when the welding width W is set to 1 / 126 or more of the inner diameter of the cylindrical container 2, a target pressure resistance of 0.6 MPa or more is achieved even if the welding efficiency is 60% or more.

[0023] The welding efficiency of the hollow fiber membrane module 1 can be measured by the following method. (1) A test piece is cut out from the hollow fiber membrane module 1 after welding, so as to include the welded portion 9. At this time, the length is adjusted so that the center position of the test piece in the tensile direction is the welded surface. (2) The test piece is held in a tensile tester, and the tensile strength is calculated by a method in accordance with JIS K 7161-2. (3) The welding efficiency is calculated by dividing the obtained tensile strength by the base material strength.

[0024] Next, a method for manufacturing the hollow fiber membrane module 1 according to an embodiment of the present invention will be described.

[0025] First, the cylindrical container 2 and the header 5 are molded from an amorphous polymer having a transmittance of 10% or more and a deflection temperature under load of 130°C or more (molding process). As such an amorphous polymer, the aforementioned polyphenylsulfone (PPSU) or polysulfone (PSU) can be used. In this embodiment, the inner diameter of the cylindrical container 2 is set to 20 to 200 mm in the molding process.

[0026] Next, the hollow fiber membrane bundle 3 is filled into the cylindrical container 2 (filling step), and then the cylindrical container 2 and the header 5 formed in the forming step are dried (drying step). The drying temperature in this drying step can be set arbitrarily, but can be set to 60°C or higher, preferably 70°C or higher, and more preferably 80°C or higher.

[0027] Next, each end of the cylindrical container 2 and the end of the header 5 are welded by infrared radiation (welding process). The welding process includes a "heating process" in which infrared radiation is applied to the welding surfaces at each end of the cylindrical container 2 and the welding surfaces at the end of the header 5 to melt the amorphous polymer on the welding surfaces; a "pressurizing process" in which pressure is applied to press the melted welding surfaces together to bond them; and a "cooling process" in which the amorphous polymer is solidified by cooling under pressure. The pressurizing process and cooling process correspond to the pressure-holding process of the present invention. In this embodiment, in the welding process, the weld width W at the welded portion 9 between the cylindrical container 2 and the header 5 is set to be equal to or greater than 1 / 211 of the inner diameter of the cylindrical container 2.

[0028] In the "heating step," the infrared output current value can be set arbitrarily, but is preferably set to 13.0 A to 15.0 A. The infrared irradiation time can be set arbitrarily, but is preferably set to 18 to 28 seconds. The distance between the welding surface and the irradiation source can be set arbitrarily, but is preferably set to 2.0 mm to 4.5 mm. In the "pressurizing step," the pressure can be set arbitrarily, but is preferably set to 500 N to 3000 N. The pressurizing time can be set arbitrarily, but is preferably set to 5 to 15 seconds. In the "cooling step," the cooling time can be set arbitrarily, but is preferably set to 5 to 15 seconds. By setting the time as described above, the hollow fiber membrane bundle 3 and potting portion 4 contained in the cylindrical container 2 can be uniformly welded in the thickness direction around the entire circumference of the cylindrical container 2 without causing damage due to infrared heat. Whether or not the entire circumference is uniformly welded in the thickness direction can be confirmed by acquiring an X-ray CT image of a cross section of the welded portion 9 along the axial direction of the cylindrical container and determining whether or not voids are present in the welded portion 9.

[0029] A sterilization step may be performed after the welding step. For example, the hollow fiber membrane module 1 may be introduced into a high-pressure steam sterilizer and sterilized with high-pressure steam. The high-pressure steam sterilization temperature can be set arbitrarily, but is preferably 120°C or higher. Furthermore, from the viewpoint of eradicating heat-resistant spore-forming bacteria (Clostridium botulinum), it is preferable to perform the sterilization at 130°C or higher, more preferably 150°C or higher. Furthermore, after being installed in a biopharmaceutical production process, the hollow fiber membrane module 1 may be subjected to stationary sterilization with high-pressure steam. Stationary sterilization is performed, for example, by passing steam at 130°C or higher, preferably 150°C or higher, from both the primary and secondary sides of a filter. By performing such high-pressure steam sterilization, a hollow fiber membrane module 1 can be produced in which high-heat-resistant bacteria such as spore-forming bacteria (Clostridium botulinum) have been eradicated.

[0030] The hollow fiber membrane module 1 according to the embodiment described above comprises a cylindrical container 2 in which a hollow fiber membrane bundle 3 is housed, and a header 5 provided at both ends of the cylindrical container 2 and having fluid inlets and outlets 5a. Each end of the cylindrical container 2 is welded uniformly in the thickness direction to the end of the header 5 around the entire circumferential direction. The cylindrical container 2 and the header 5 are made of an amorphous polymer (e.g., polyphenylsulfone (PPSU) or polysulfone (PSU) which has excellent resistance to high pressure and high temperature) having a transmittance of 10% or more and a deflection temperature under load of 130°C or more. The weld width W at the welded portion 9 between the cylindrical container 2 and the header 5 is 1 / 211 or more of the inner diameter of the cylindrical container 2, and therefore can withstand high-temperature sterilization prior to the virus removal step, and there is no leakage of chemical solution from the header during high-pressure filtration.

[0031] Furthermore, in the hollow fiber membrane module 1 according to the embodiment described above, by keeping the size of the cylindrical container 2 made of a specific amorphous polymer within an appropriate range, it is possible to suppress dimensional variations during injection molding of the cylindrical container 2, and thereby suppress problems in joining the cylindrical container 2 and the header 5. Furthermore, while the pressure resistance of the cylindrical container 2 (and therefore the module 1) decreases as the inner diameter increases, setting an upper limit on the inner diameter makes it possible to ensure pressure resistance.

[0032] Furthermore, in the hollow fiber membrane module 1 according to the embodiment described above, the recess 4d is formed between the end of the cylindrical container 2 that forms the welded portion 9 and the protrusion 4c provided in the central region 4b at both ends of the potting portion 4. Therefore, even if burrs protruding in the radial direction are generated when welding the end of the cylindrical container 2 and the end of the header 5, the burrs can escape into the recess 4d.

[0033] Furthermore, in the hollow fiber membrane module 1 according to the embodiment described above, the side surface 4cb of the convex portion 4c of the potting portion 4 is inclined at an angle of 90 to 130° in side view with respect to the cut surface 4ca of the potting portion 4 (the surface formed by cutting both ends of the convex portion 4 in the radial direction), so that the space of the concave portion 4d can be expanded radially toward the tip side of the potting portion 4. Therefore, burrs generated during welding can be effectively removed.

[0034] Furthermore, in the hollow fiber membrane module 1 according to the embodiment described above, since a lower limit is set for the inner diameter of the nozzle 6, it is possible to suppress the occurrence of pressure loss and to suppress a decrease in treatment efficiency even when the treatment liquid flows at a relatively high speed. That is, when the inner diameter of the nozzle 6 is 6.0 mm or more, the pressure loss during filtration at 343 kPa tends to be suppressed to less than 5%, when the inner diameter of the nozzle 6 is 6.7 mm or more, the pressure loss tends to be suppressed to less than 3%, and when the inner diameter of the nozzle 6 is 8.9 mm or more, the pressure loss tends to be suppressed to less than 1%.

[0035] Furthermore, in the hollow fiber membrane module 1 according to the embodiment described above, the cylindrical container 2 has a uniform thickness, which tends to ensure the strength of the cylindrical container 2. Furthermore, a cylindrical container 2 with a uniform thickness tends to be easier to injection mold. Note that, in the embodiment described above, the uniform thickness of the cylindrical container 2 means that the thickness is uniform within a range of ±10% from the average value in the circumferential direction and the axial direction of the cylindrical container.

[0036] Furthermore, the hollow fiber membrane module 1 according to the embodiment described above employs a cylindrical tubular container 2, which has the advantage that stress is evenly distributed when internal pressure acts on the tubular container 2, making it less likely for strength to vary. Furthermore, the higher the circularity of the tubular container 2, the greater the bonding strength with the potting part 4 can be.

[0037] Furthermore, in the manufacturing method according to the embodiment described above, the cylindrical container 2 and the header 5 are molded from a specific amorphous polymer, so the hollow fiber membrane module 1 manufactured by this method can withstand high-pressure, high-heat sterilization that occurs before the virus removal step. Furthermore, each end of the cylindrical container 2 made from this specific amorphous polymer is welded to the end of the header 5 by infrared irradiation, so the cylindrical container 2 and the header 5 can be reliably joined (even components made from an amorphous polymer that is resistant to high heat can be reliably joined by infrared welding).

[0038] Furthermore, in the manufacturing method according to the embodiment described above, the weld width W at the welded portion 9 between the cylindrical container 2 and the header 5 is set to a specific value, which tends to improve the pressure resistance.

[0039] Furthermore, in the manufacturing method according to the embodiment described above, by keeping the size of the cylindrical container 2 made of a specific amorphous polymer within an appropriate range, it is possible to suppress dimensional variations during injection molding of the cylindrical container 2, and thereby suppress problems in joining the cylindrical container 2 and the header 5. Furthermore, while the pressure resistance of the cylindrical container 2 (and therefore the module 1) decreases as the inner diameter increases, setting an upper limit on the inner diameter makes it possible to ensure pressure resistance.

[0040] Furthermore, the manufacturing method according to the embodiment described above includes a drying process for drying the cylindrical container 2 and the header 5 before infrared irradiation, so that infrared welding between the cylindrical container 2 and the header 5 can be performed well.

[0041] Furthermore, the manufacturing method according to the embodiment described above includes a pressure holding process (pressurizing process and cooling process) in which the two ends of the cylindrical container and the end of the header 5 are pressed together under infrared irradiation, thereby making it possible to more reliably join the end of the cylindrical container 2 and the end of the header 5.

[0042] Next, an embodiment of the present invention will be described.

[0043] A welding test was conducted using an amorphous polymer and a crystalline polymer. Specifically, a pair of sample members (welding width 4 mm) prepared using polypropylene (PP), a crystalline polymer, and polyphenylsulfone (PPSU), polycarbonate (PC), and polysulfone (PSU), which are amorphous polymers with a transmittance of 10% or more and a deflection temperature under load of 130°C or more, were welded using infrared welding, vibration welding, a combination of infrared welding and vibration welding, and laser welding. The welding efficiency was calculated from the tensile strength of the welded portion and the tensile strength of the base material. The welding efficiency was calculated using the following formula: (welding efficiency) = {(tensile strength of the welded portion) / (tensile strength of the base material)} × 100. The tensile strength test was conducted using a tensile testing machine in accordance with JIS K 7161-2.

[0044] As a result, as shown in Table 1, when an amorphous polymer was used, the tensile strength of the welded portion was equivalent to that of the base material (i.e., welding efficiency was nearly 100%) for all welding methods except laser welding, and the welding efficiency was 80-90% for laser welding. On the other hand, when a crystalline polymer was used, the welding efficiency was only 50-60% for all welding methods except laser welding, and the welding efficiency for laser welding was 0%. These results confirmed that when an amorphous polymer with a transmittance of 10% or more and a deflection temperature under load of 130°C or more is used, the tensile strength of the welded portion can be ensured to be 80% or more of the tensile strength of the base material (i.e., welding efficiency of 80% or more), regardless of which of the above welding methods is adopted.

[0045]

[0046] Example 1 The cylindrical container 2 and header 5 used in a hollow fiber membrane module 1 (inner diameter 200 mm) were molded (molding process) using polyphenylsulfone (PPSU) (thickness T = 2.5 mm), an amorphous polymer with a transmittance of 10% or more and a deflection temperature under load of 130°C or more. After a filling process and a drying process at 80°C, the end 2a of the cylindrical container 2 and the end 5a of the header 5 were welded by infrared welding (welding process). In the "heating process" of the welding process, infrared rays were irradiated onto the end 2a of the cylindrical container 2 and the end 5a of the header 5 to melt the amorphous polymer on the welding surfaces. The infrared output current was set to 15.0 A, the infrared irradiation time was set to 24 seconds, and the distance between the welding surfaces and the irradiation source was set to 2.3 mm. Furthermore, in the "pressurizing process" of pressing the melted welding surfaces together with pressure, the applied pressure was set to 1000 N and the pressurizing time was set to 10 seconds. Furthermore, in the "cooling step" in which the amorphous polymer is solidified by cooling under pressure, the cooling time is set to 10 seconds. The weld width W is 2.5 mm. The hollow fiber membrane module 1 manufactured through these steps has a welding efficiency of 100%, the welded portion 9 is uniformly welded in the thickness direction over the entire circumference, and the pressure resistance exceeds 0.6 MPa.

[0047] Example 2 The cylindrical container 2 and header 5 used in the hollow fiber membrane module 1 (inner diameter 140 mm) were molded (molding process) using polyphenylsulfone (PPSU) (thickness T = 2.5 mm), an amorphous polymer with a transmittance of 10% or more and a deflection temperature under load of 130°C or more. After a filling process and a drying process at 80°C, the end 2a of the cylindrical container 2 and the end 5a of the header 5 were welded by infrared welding (welding process). In the "heating process" of the welding process, infrared rays were irradiated onto the end 2a of the cylindrical container 2 and the end 5a of the header 5 to melt the amorphous polymer on the welding surfaces. The infrared output current was set to 15.0 A, the infrared irradiation time was set to 24 seconds, and the distance between the welding surfaces and the irradiation source was set to 2.3 mm. Furthermore, in the "pressurizing process" of pressing the melted welding surfaces together with pressure, the applied pressure was set to 1000 N and the pressurizing time was set to 10 seconds. Furthermore, in the "cooling step" in which the amorphous polymer is solidified by cooling under pressure, the cooling time is set to 10 seconds. The weld width W is 2.5 mm. The hollow fiber membrane module 1 manufactured through these steps has a welding efficiency of 100%, the welded portion 9 is uniformly welded in the thickness direction over the entire circumference, and the pressure resistance exceeds 1.0 MPa.

[0048] Example 3 The cylindrical container 2 and header 5 used in the hollow fiber membrane module 1 (inner diameter 60 mm) were molded (molding process) using polyphenylsulfone (PPSU) (thickness T = 2.5 mm), an amorphous polymer with a transmittance of 10% or more and a deflection temperature under load of 130°C or more. After a filling process and a drying process at 80°C, the end 2a of the cylindrical container 2 and the end 5a of the header 5 were welded by infrared welding (welding process). In the welding process, in the "heating process" in which infrared rays are irradiated onto the end 2a of the cylindrical container 2 and the end 5a of the header 5 to melt the amorphous polymer on the welding surfaces, the infrared output current value was set to 15.0 A, the infrared irradiation time was set to 24 seconds, and the distance between the welding surfaces and the irradiation source was set to 2.3 mm. In addition, in the "pressurizing process" in which the melted welding surfaces are pressed together by pressure, the pressure was set to 1000 N and the pressure time was set to 10 seconds. Furthermore, in the "cooling step" in which the amorphous polymer was solidified by cooling under pressure, the cooling time was set to 10 seconds. The weld width W was 2.5 mm. The hollow fiber membrane module 1 manufactured through this process had a welding efficiency of 100% and a pressure resistance of over 2.5 MPa. Figure 4 shows an X-ray CT image (a) of a cross section of the welded portion 9 of the hollow fiber membrane module 1 manufactured in this manner, taken along the axial direction of the cylindrical vessel, and an X-ray CT image (b) of the welded portion 9 viewed from above. As is clear from Figures 4(a) and (b), the weld was uniformly formed in the thickness direction around the entire periphery of the welded surface.

[0049] In this example, a hollow fiber membrane (virus removal membrane: membrane area 0.3 m) prepared by the method described in WO 2016 / 031834 was used. ２ The hollow fiber membrane module 1 fabricated as described above using the above-mentioned membrane was subjected to high-pressure steam sterilization three times at 134°C for 30 minutes. The PP7 phage removal ability was then confirmed using the method described in PDA Technical Report 41. The LRV was found to be 7.3, confirming high virus removal performance. Furthermore, pure water was filtered at 400 kPa, and no liquid leaked from the header.

[0050] Example 4 The cylindrical container 2 and header 5 used in the hollow fiber membrane module 1 (inner diameter 40.4 mm) were molded (molding process) using polyphenylsulfone (PPSU) (thickness T = 1.4 mm), an amorphous polymer with a transmittance of 10% or more and a deflection temperature under load of 130°C or more. After a filling process and a drying process at 80°C, the end 2a of the cylindrical container 2 and the end 5a of the header 5 were welded by infrared welding (welding process). In the welding process, in the "heating process" in which infrared rays are irradiated onto the end 2a of the cylindrical container 2 and the end 5a of the header 5 to melt the amorphous polymer on the welding surfaces, the infrared output current value was set to 15.0 A, the infrared irradiation time was set to 20 seconds, and the distance between the welding surfaces and the irradiation source was set to 2.3 mm. In addition, in the "pressurizing process" in which the melted welding surfaces are pressed together by pressure, the pressure was set to 500 N and the pressure time was set to 10 seconds. Furthermore, in the "cooling step" in which the amorphous polymer is solidified by cooling under pressure, the cooling time was set to 10 seconds. The welding width W was 1.4 mm. The hollow fiber membrane module 1 manufactured through these steps had a welding efficiency of 100% and a pressure resistance of more than 1.3 MPa.

[0051] Comparative Example: A cylindrical container 2 and a header 5 used in a hollow fiber membrane module 1 (inner diameter 60 mm) were molded (molding process) using polyphenylsulfone (PPSU) (thickness T = 2.5 mm), an amorphous polymer having a transmittance of 10% or more and a deflection temperature under load of 130°C or more. After a filling process and a drying process at 45°C, the end 2a of the cylindrical container 2 and the end 5a of the header 5 were welded by infrared welding (welding process). In the welding process, in the "heating process" in which infrared rays are irradiated onto the end 2a of the cylindrical container 2 and the end 5a of the header 5 to melt the amorphous polymer on the welding surfaces, the infrared output current value was set to 15.0 A, the infrared irradiation time was set to 20 seconds, and the distance between the welding surfaces and the irradiation source was set to 2.3 mm. In addition, in the "pressurizing process" in which the melted welding surfaces are pressed together by pressure, the pressure was set to 1000 N and the pressure time was set to 10 seconds. Furthermore, in the "cooling step" in which the amorphous polymer was solidified by cooling under pressure, the cooling time was set to 10 seconds. The weld width W was 2.5 mm. The pressure resistance of the hollow fiber membrane module 1 produced through this process was less than 0.5 MPa. Figure 5 shows X-ray CT images (a) of a cross section of the welded portion 9 of the hollow fiber membrane module 1 produced in this manner, taken along the axial direction of the cylindrical vessel, and (b) of the welded portion 9 as viewed from above. As shown in Figures 5(a) and 5(b), voids were observed in some areas, indicating that uniform welding in the thickness direction had not been achieved.

[0052] In this comparative example, a hollow fiber membrane (virus removal membrane: membrane area 0.3 m) prepared by the method described in WO 2016 / 031834 was used. ２ When the hollow fiber membrane module 1 fabricated as described above using the above-mentioned filtration membrane 1 was pressurized to 0.6 MPa using a water pressure pump, water leakage from the header was confirmed.

[0053] The present invention is not limited to the above-described embodiments and examples, and any design modifications made by a person skilled in the art to these embodiments and examples as appropriate are also included within the scope of the present invention as long as they comprise the features of the present invention. In other words, the elements of the above-described embodiments and examples, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those exemplified and can be modified as appropriate. Furthermore, the elements of the above-described embodiments and examples can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they comprise the features of the present invention.

[0054] INDUSTRIAL APPLICABILITY The present invention is useful for providing a hollow fiber membrane module for virus removal that is resistant to high pressure and high heat, and for providing a method for producing the same.

[0055] DESCRIPTION OF SYMBOLS 1... Hollow fiber membrane module 2... Cylindrical container 2a... End 3... Hollow fiber membrane bundle 4... Potting portion 4b... Central region of both ends 4c... Convex portion 4ca... Cut surface 4cb... Side surface 4d... Concave portion 5... Header 5a... End 5b... Fluid inlet / outlet 6... Nozzle 9... Welded portion W... Welded width

Claims

1. A hollow fiber membrane module comprising a cylindrical container that houses a hollow fiber membrane bundle, and headers that are provided at both ends of the cylindrical container and have inlets and outlets for fluids, wherein each end of the cylindrical container is welded to the end of the header around its entire circumference, the cylindrical container and the header are made of an amorphous polymer with a permeability of 10% or more and a deflection temperature under load of 130°C or more, and the weld width at the welded part between the cylindrical container and the header is 1 / 211 or more of the inner diameter of the cylindrical container.

2. The hollow fiber membrane module according to claim 1, wherein the inner diameter of the cylindrical container is set to 20 to 200 mm.

3. A hollow fiber membrane module according to claim 1 or 2, further comprising potting sections for embedding and fixing the hollow fiber membrane bundle at both ends of the cylindrical container, wherein a convex section protruding toward the header is provided in the central region of both ends of the potting section, thereby forming a concave section between the end of the cylindrical container forming the welded section and the convex section of the potting section.

4. A hollow fiber membrane module according to claim 3, wherein cut surfaces are formed at both ends of the convex portion by cutting the convex portion in the radial direction, and the side surfaces of the convex portion are inclined at an angle of 90 to 130° with respect to the cut surfaces in a side view.

5. A hollow fiber membrane module according to any one of claims 1 to 4, wherein the cylindrical container has a nozzle which is an inlet and outlet for fluid, and the inner diameter of the nozzle is 6.0 mm or more.

6. The hollow fiber membrane module according to any one of claims 1 to 5, wherein the cylindrical container has a uniform thickness.

7. The hollow fiber membrane module according to any one of claims 1 to 6, wherein the amorphous polymer is polyphenylsulfone (PPSU) or polysulfone (PSU).

8. The hollow fiber membrane module according to any one of claims 1 to 7, wherein the cylindrical container is a cylinder.

9. The hollow fiber membrane module according to any one of claims 1 to 8, which is used for removing viruses.

10. A method for manufacturing a hollow fiber membrane module comprising a cylindrical container and headers provided at both ends of the cylindrical container, the method comprising a welding step of welding each end of the cylindrical container to the end of the header by infrared irradiation, wherein the cylindrical container and the header are made of an amorphous polymer having a transmittance of 10% or more and a deflection temperature under load of 130°C or more.

11. The manufacturing method according to claim 10, wherein in the welding step, the welding width at the welded portion between the cylindrical container and the header is set to 1 / 211 or more of the inner diameter of the cylindrical container.

12. The manufacturing method according to claim 10 or 11, wherein the cylindrical container has an inner diameter of 20 to 200 mm.

13. The manufacturing method according to any one of claims 10 to 12, further comprising a drying step of drying the cylindrical container and the header before the infrared irradiation.

14. The manufacturing method according to any one of claims 10 to 13, further comprising a step of filling the hollow fiber membrane bundle into the cylindrical container before the infrared irradiation.

15. A manufacturing method according to any one of claims 10 to 14, wherein the welding step includes a pressure holding step of pressing the end of the cylindrical container and the end of the header together under infrared irradiation.

16. The manufacturing method according to any one of claims 10 to 15, further comprising a step of high-pressure steam sterilization at 130°C or higher.

17. The manufacturing method according to any one of claims 10 to 16, wherein the amorphous polymer is polyphenylsulfone (PPSU) or polysulfone (PSU).

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