Porous multilayer hollow fiber membrane and method for manufacturing same

Abstract

According to one embodiment of the present invention, provided is a porous multilayer hollow fiber membrane and a method for manufacturing same, wherein the porous multilayer hollow fiber membrane comprises: a hollow body; a first layer formed on an outer surface of the hollow body; and a second layer formed on an outer surface of the first layer, and has a water permeability higher than a predetermined value and is capable of removing viruses.

Description

Porous multilayer hollow fiber membrane and method for manufacturing the same

[0001] The present invention relates to a porous multilayer hollow fiber membrane and a method for manufacturing the same.

[0002] Recently, as environmental pollution, especially water pollution, has become a social problem, the use of water purification devices that physically or chemically filter water to remove impurities is increasing.

[0003] These water purification systems filter out various harmful substances contained in raw water, such as tap water or groundwater, converting it into safe and sanitary drinking water. Conventional water purification systems utilize multiple filters to remove harmful substances and filter out suspended solids from raw water.

[0004] These water purification devices may be equipped with various filters to filter raw water, and the filters are generally configured to include various filter media in a housing formed in a hollow cylindrical shape to filter raw water. The filters mainly used include pre-carbon filters, ultrafiltration filters, reverse osmosis filters, sediment filters, and post-carbon filters.

[0005] The hollow fibers in a double-layer hollow fiber membrane refer to hollow fibers, and a hollow fiber membrane is a separation membrane (filter) utilizing hollow fibers. Membranes, used to separate specific components such as gases, liquids, or solids, particularly ionic substances, are designed to selectively pass or reject specific components. They are designed to have selectivity for the substances to be separated, while also allowing the substances to pass through with low resistance.

[0006] In the manufacturing method of hollow fiber membranes, the nonsolvent induced phase separation (NIPS) method, which casts and extrudes a polymer solution at a low temperature where phase separation does not occur due to heat, solidifies it in a nonsolvent, and forms a porous structure, and the thermally induced phase separation method, which manufactures a membrane by spinning it at a temperature higher than the temperature at which phase separation occurs due to heat, and then cooling and solidifying it, have been generally used.

[0007] However, although the production of hollow fiber membranes by the heat-induced phase separation method is easier than that by the non-solvent-induced phase separation method, there is a problem in that it is difficult to control the pore size, making it difficult to remove viruses.

[0008] [Prior Art Literature]

[0009] [Patent Document]

[0010] (Patent Document 0001) Republic of Korea Patent Publication No. 10-2345697 (Registration Date: December 28, 2021)

[0011] The present invention has been devised to solve the above-mentioned technical problem, and its purpose is to provide a porous multilayer hollow fiber membrane having both dense pores and high water permeability, and a method for manufacturing the same.

[0012] The purpose of the present invention is to provide a porous multilayer hollow fiber membrane having micropores capable of providing viruses and excellent water permeability, and a method for manufacturing the same.

[0013] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0014] A porous multilayer hollow fiber membrane according to one embodiment of the present invention is:

[0015] hollow;

[0016] A first layer formed on the outer surface of the hollow body; and

[0017] A second layer formed on the outer surface of the first layer may be included to have a water permeability higher than a predetermined value and to enable removal of viruses.

[0018] According to one embodiment of the present invention,

[0019] The first layer is formed to a thickness of 150 μm to 250 μm,

[0020] The second layer may be formed to a thickness of 5 μm to 150 μm.

[0021] According to one embodiment of the present invention,

[0022] The above predetermined figure may be 1,500LMH.

[0023] According to one embodiment of the present invention,

[0024] It can be formed into pores with a diameter of 0.02 to 0.1 μm.

[0025] According to one embodiment of the present invention,

[0026] The first layer and the second layer,

[0027] By using a hollow fiber molding nozzle having multiple annular discharge ports, a solution containing an additive and a polymer resin dissolved in a solvent can be discharged from the annular discharge ports into a non-solvent.

[0028] According to one embodiment of the present invention,

[0029] The above polymer resin is,

[0030] It may contain at least one of polysulfone, polyethersulfone, polyacrylonitrile, polyethylene, polyimide, polyamide, polyetherimide, cellulose acetate, and polyvinylidene fluoride.

[0031] According to one embodiment of the present invention,

[0032] Certain additives are,

[0033] It may contain at least one of polyvinyl pyrrolidone (PVP K30), delonized water (DW), citric acid (CA), and lactic acid (LA).

[0034] According to one embodiment of the present invention,

[0035] The above solvent is,

[0036] It may contain at least one of 1-Methyl-2-Pyrrolidone, Dimethylacetamide, and Dimethylsulfoxide.

[0037] According to one embodiment of the present invention,

[0038] When the thickness of the film of the second layer is K and the thickness of the film of the first layer is L, And, When , the following mathematical expression 1 can be satisfied.

[0039]

[0040] [Mathematical Formula 1]

[0041]

[0042]

[0043] (In the above mathematical formula, W is the water permeability, K is the thickness of the membrane of the second layer, L is the thickness of the membrane of the first layer, and , is a constant that increases proportionally as water permeability increases)

[0044]

[0045] A porous multilayer hollow fiber membrane according to one embodiment of the present invention is:

[0046] A plurality of layers are formed, including a first layer formed on the outer surface of the hollow body with a thickness of 200 μm and a second layer formed on the outer surface of the first layer with a thickness of 100 μm, and can be included to have a water permeability higher than a predetermined value and to enable removal of viruses.

[0047] A method for manufacturing a porous multilayer hollow fiber membrane according to one embodiment of the present invention is as follows:

[0048] A solution preparation step for preparing each solution forming multiple layers;

[0049] A radiating step of radiating a plurality of the solutions prepared in the above liquefaction step into a nozzle including a plurality of circular discharge ports into a coagulation tank; and

[0050] It may include a winding step of winding the sediment that has undergone a phase change in the above radiation step onto a winding roll.

[0051] According to one embodiment of the present invention,

[0052] The above step of the liquid phase is,

[0053] A first solution preparation step for preparing a first solution to form a first layer according to predetermined steps; and

[0054] It may include a second solution preparation step of preparing a second solution to form a second layer according to predetermined steps.

[0055] According to one embodiment of the present invention,

[0056] The above solution is,

[0057] It can be formed by dissolving additives and polymer resins in a solvent in predetermined amounts.

[0058] According to one embodiment of the present invention,

[0059] The above polymer resin is,

[0060] It may contain at least one of polysulfone, polyethersulfone, polyacrylonitrile, polyethylene, polyimide, polyamide, polyetherimide, cellulose acetate, and polyvinylidene fluoride.

[0061] According to one embodiment of the present invention,

[0062] The above additives are,

[0063] It may contain at least one of polyvinyl pyrrolidone (PVP K30), delonized water (DW), citric acid (CA), and lactic acid (LA).

[0064] According to one embodiment of the present invention,

[0065] The above solvent is,

[0066] It may contain at least one of 1-Methyl-2-Pyrrolidone, Dimethylacetamide, and Dimethylsulfoxide.

[0067]

[0068] According to one embodiment of the present invention, a porous multilayer hollow fiber membrane having both dense pores and high water permeability and a method for manufacturing the same can be provided.

[0069] According to one embodiment of the present invention, a porous multilayer hollow fiber membrane capable of providing a virus and having excellent water permeability and a method for manufacturing the same can be provided.

[0070] Figures 1 and 2 are photographs of the surface and cross-section of the first layer of a porous multilayer hollow fiber membrane according to one embodiment of the present invention taken with an electron microscope at a magnification of 5,000 times.

[0071] Figures 3 and 4 are photographs of the surface and cross-section of the second layer of the porous multilayer hollow fiber membrane according to one embodiment of the present invention taken with an electron microscope at a magnification of 5,000 times.

[0072] Figure 5 is a flow chart of a method for manufacturing a porous multilayer hollow fiber membrane according to one embodiment of the present invention.

[0073] Hereinafter, one embodiment of a porous multilayer hollow fiber membrane and a method for manufacturing the same according to the present invention will be described in detail with reference to the attached drawings.

[0074] When assigning reference numerals to components in each drawing, it should be noted that identical components are assigned the same numerals whenever possible, even if they appear on different drawings. Furthermore, when describing embodiments of the present invention, if a detailed description of a related known configuration or function is deemed to hinder understanding of the embodiments of the present invention, the detailed description will be omitted.

[0075] In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0076]

[0077] Filters for water purification can be broadly classified into four types, and these four types of filters can be classified into microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) depending on the membrane rectification.

[0078] In general, microfiltration (MF) can be 0.1 to 10 μm, ultrafiltration (UF) 10 to 100 nm, nanofiltration (NF) 1 to 10 nm, and reverse osmosis (RO) 1 nm or less. Microfiltration filters can control turbidity and remove various bacteria, and ultrafiltration filters can remove high molecular weight organic substances and various viruses. While ultrafiltration filters can remove various viruses, they have the problem of low water permeability, and while microfiltration has high water permeability, it has the problem of difficulty in removing viruses.

[0079] A porous multilayer hollow fiber membrane according to one embodiment of the present invention can form a high water permeability comparable to that of MF hollow fiber while having microscopic pores capable of removing viruses. More specifically, the water permeability comparable to that of MF hollow fiber may mean a water permeability of 3000LMH or higher, but is not limited thereto.

[0080]

[0081] Generally, an organic compound that dissolves a polymer is called a solvent, and an organic compound that does not dissolve a polymer is called a nonsolvent. Nonsolvent-induced phase separation (NIPS) is a method for selectively precipitating a polymer by adding a nonsolvent to a homogeneous polymer solution.

[0082] First, when a polymer is dissolved in a solvent, a homogeneous one-phase solution is formed. However, when a nonsolvent is added, the already dissolved polymer precipitates again, resulting in phase separation into two phases: a rich phase and a lean phase. At this time, the solvent and nonsolvent must be miscible.

[0083] When a polymer solution is immersed in a non-solvent, small nuclei of the polymer lean phase are created within the polymer rich phase, and these nuclei continue to grow until the surrounding polymer rich phase solidifies through crystallization, gelation, etc. At this time, the nuclei coalesce or aggregate and evaporate to form pores, and structural differences may occur depending on the degree of solvent / non-solvent mixing.

[0084]

[0085] According to one embodiment of the present invention, by using a hollow fiber forming nozzle having two or more annular discharge ports arranged in a deep circular manner, a solution of a polymer resin mixed with an additive and dissolved in a solvent is discharged into a non-solvent through one or more annular discharge ports, thereby forming a porous multilayer hollow fiber membrane. The porous multilayer hollow fiber membrane formed by the non-solvent-induced phase separation method may include micropores formed therein to enable the removal of viruses.

[0086]

[0087] FIGS. 1 and 2 are photographs of the surface and cross-section of a first layer of a porous multilayer hollow fiber membrane according to an embodiment of the present invention taken with an electron microscope at a magnification of 5,000 times, and FIGS. 3 and 4 are photographs of the surface and cross-section of a second layer of a porous multilayer hollow fiber membrane according to an embodiment of the present invention taken with an electron microscope at a magnification of 5,000 times.

[0088]

[0089] Specifically, in one embodiment of the present invention, a porous multilayer hollow fiber membrane has a hollow portion located in the center, and a porous multilayer membrane can be formed along the outer periphery of the hollow portion.

[0090] Here, the hollow fiber diameter may range from 250 to 500 μm, but is not limited thereto. If the hollow fiber diameter is 250 μm or greater, the pressure loss of the liquid flowing within the hollow fiber will not be excessively large. If the hollow fiber diameter is 500 μm or less, sufficient compressive strength and burst strength can be easily achieved with a relatively thin film thickness. Preferably, the inner diameter may range from 300 to 450 μm.

[0091] A plurality of porous multilayer membranes can be formed on the outer circumferential surface of the hollow portion of the porous multilayer hollow fiber membrane, and the thickness of the membrane of the inner diameter side of the hollow fiber membrane formed on the outer circumferential surface of the hollow portion, i.e., the first layer, can be formed to be 150 µm to 250 µm, and the thickness of the membrane of the outer diameter side formed on the outer circumferential surface of the first layer, i.e., the second layer, can be formed to be 5 µm to 150 µm. Preferably, the first layer can be formed to be 150 µm to 250 µm, and the second layer can be formed to be 50 µm to 150 µm, and more preferably, the first layer can be formed to be 200 µm, and the second layer can be formed to be 100 µm, but is not limited thereto. In addition, the porous multilayer hollow fiber membrane can be formed with a pore size of 0.02 to 0.1 μm, and by forming a pore size with a diameter of 0.02 to 0.1 μm, it can form a high water permeability while easily removing viruses. Here, high water permeability may mean a water permeability of 1,500 LMH or more, but is not limited thereto.

[0092] Preferably, the first layer is formed to have a thickness of 150 μm to 250 μm, and the second layer is formed to have a thickness of 50 μm to 150 μm, so that the plurality of membranes surrounding the hollow space can be formed to have a thickness of 200 to 400 μm. If the membrane thickness is less than 200 μm, it is difficult to exhibit sufficient compressive strength or burst strength, and if it is more than 400 μm, it is difficult to exhibit sufficient water permeability, which is a disadvantage. More preferably, the plurality of membranes surrounding the hollow space can be formed to have a thickness of 300 μm, but is not limited thereto.

[0093]

[0094] According to one embodiment of the present invention, a porous multilayer hollow fiber membrane can be formed by spinning a solvent containing a polymer resin dissolved together with an additive into a coagulation tank containing a non-solvent through a nozzle to invert the solvent and winding it onto an immersion roll. At this time, by spinning polymer resin solutions having different compositions from nozzles having adjacent annular discharge ports, a multilayer membrane having different pore sizes in adjacent layers can be obtained. Different compositions may refer to a case where the constituent materials of the solvent in which the polymer resin is dissolved are different, or a case where the constituent materials are the same but the composition ratio is different. Even for the same polymer resin, if the molecular weight or molecular weight distribution is clearly different, the constituent materials are considered to be different. The confluence location of the solvent in which the polymer resins dissolved with different compositions may be the bottom surface of the nozzle, but is not limited thereto.

[0095]

[0096] According to one embodiment of the present invention, a porous multilayer hollow fiber membrane can be formed by spraying a solvent containing a polymer resin and an additive in a predetermined content range into a coagulation tank through a hollow fiber forming nozzle having two or more concentrically arranged annular discharge ports, thereby inducing non-solvent phase separation and solidifying, and winding the membrane onto an immersion roll as needed. A first solution for forming a first layer and a second solution for forming a second layer can be sprayed through each of the plurality of discharge ports of the nozzle.

[0097]

[0098] The polymer resin included in the manufacture of the porous multilayer hollow fiber membrane may include at least one of polysulfone, polyethersulfone (PES), polyacrylonitrile, polyethylene, polyimide, polyamide, polyetherimide, cellulose acetate, and polyvinylidene fluoride, but is not limited thereto.

[0099] The solvent included in the production of the porous multilayer hollow fiber membrane may include at least one of 1-methyl-2-pyrrolidone, dimethylacetamide, and dimethylsulfoxide, but is not limited thereto.

[0100] The additives included in the manufacture of the porous multilayer hollow fiber membrane may include at least one of polyvinyl pyrrolidone (PVP K30), polyethylene glycol, delonized water (DW), citric acid (CA), and lactic acid (LA), but are not limited thereto.

[0101]

[0102] The second solution forming the second layer of the porous multilayer hollow fiber membrane can be prepared by mixing at least one of a polymer resin, an additive, and a solvent in a predetermined amount.

[0103] The predetermined content of the second solution may be a mixed solution containing, but is not limited to, 5 to 20 wt% of polysulfone, 65 to 80 wt% of dimethylacetamide, 5 to 15 wt% of polyvinyl pyrrolidone (PVP K30), 1 to 10 wt% of polyethylene glycol, 1 to 5 wt% of delonized water (DW), and 1 to 1 wt% of lactic acid (LA), based on the total weight% of the second solution.

[0104] Preferably, the second solution may be a mixed solution containing 17 wt% of polysulfone, 68.85 wt% of dimethylacetamide, 7.45 wt% of polyvinyl pyrrolidone (PVP K30), 4 wt% of polyethylene glycol, 1.2 wt% of delonized water (DW), and 1.5 wt% of lactic acid (LA).

[0105]

[0106] The first solution used for forming the first layer of the porous multilayer hollow fiber membrane can be prepared by mixing at least one of a polymer resin, an additive, and a solvent in a predetermined amount.

[0107] The above-determined content of the first solution may be a mixed solution containing, but is not limited to, 5 to 20 wt% of polysulfone, 65 to 80 wt% of dimethylacetamide, 5 to 15 wt% of polyvinyl pyrrolidone (PVP K30), 1 to 5 wt% of delonized water (DW), and 1 to 5 wt% of citric acid (CA), based on the total weight% of the first solution.

[0108] Preferably, the first solution may be a mixed solution containing 13.5 wt% of polysulfone, 63.3 wt% of dimethylacetamide, 9.5 wt% of polyvinyl pyrrolidone (PVP K30), 1.2 wt% of delonized water (DW), and 2.5 wt% of citric acid (CA).

[0109]

[0110] A porous multilayer hollow fiber membrane can be formed with multiple layers having different densities. The multiple layers include multiple layers including a first layer and a second layer, and the pores of the first layer can be formed to have a pore size that is larger than a predetermined value or more than the pores of the second layer. Preferably, the pores of the first layer can be formed to have a pore size that is 1,000 times larger than the pores of the second layer, but is not limited thereto. The pores of the second layer can be formed to have a smaller pore size than the pores of the first layer, and the pores of the second layer can be formed to have a smaller pore size than the pores of the first layer, thereby removing viruses from the second layer and preventing contamination of the hollow fiber membrane.

[0111]

[0112] When the thickness of the hollow fiber membrane is limited to a predetermined value, as the thickness of the first layer increases, the thickness of the second layer decreases, so that the thickness of the second layer can be determined according to the thickness of the first layer, and accordingly, the water permeability can be proportionally determined according to the thickness of the first layer. The hollow fiber membrane can be formed with a predetermined thickness, and when the hollow fiber membrane is formed with a predetermined thickness, the water permeability can be formed by the difference in pore diameters of the pores provided in each of the first and second layers. More specifically, the pores of the first layer can be formed with a larger pore diameter than the pores of the second layer. As the first layer having a larger pore diameter than the pores of the second layer becomes thicker, the water permeability increases, and as the thickness of the second layer having a smaller pore diameter than the pores of the first layer becomes thicker, the water permeability can decrease.

[0113] More specifically, when the film thickness of the first layer is K and the film thickness of the second layer is L, And, When , the following mathematical expression 1 can be satisfied.

[0114]

[0115] [Mathematical Formula 1]

[0116]

[0117] (In the above mathematical formula, W is the water permeability, K is the thickness of the membrane of the second layer, L is the thickness of the membrane of the first layer, and the thickness of the hollow fiber membrane , is a constant that increases proportionally as water permeability increases)

[0118]

[0119] In addition, when a is the lowest constant of the ratio of the thickness of the film of the first layer to the thickness of the film of the second layer, and b is the highest constant of the ratio of the thickness of the film of the first layer to the thickness of the film of the second layer, the following mathematical expression 2 may be satisfied. Preferably, a may be included as 5 or less, and b may be included as 1.5 or more, but is not limited thereto.

[0120]

[0121] [Equation 2]

[0122]

[0123]

[0124] (In the above mathematical formula, K is the thickness of the film of the second layer, L is the thickness of the film of the first layer, a is the lowest constant of the ratio of the thickness of the film of the first layer to the thickness of the film of the second layer, and b is the highest constant of the ratio of the thickness of the film of the second layer to the thickness of the film of the first layer)

[0125]

[0126] This porous multilayer hollow fiber membrane with a desirable structure has high water permeability and micropores formed, so it can remove viruses while maintaining high water permeability.

[0127]

[0128] Figure 5 is a flow chart of a method for manufacturing a porous multilayer hollow fiber membrane according to one embodiment of the present invention.

[0129] The method for manufacturing a porous multilayer hollow fiber membrane according to FIG. 5 may include a step of preparing solutions (S100) for preparing each solution forming a plurality of layers, a step of spinning (S200) for spinning a plurality of the solutions prepared in the step of spinning (S100) into a nozzle including a plurality of discharge ports so as to be radiated from each of the discharge ports into a coagulation tank, and a step of winding (S300) for winding the precipitate phase-transformed in the step of spinning (S200) onto a winding roll.

[0130] The above-described liquid preparation step (S100) can prepare each solution forming a plurality of layers. A plurality of solutions can be prepared to form each of the plurality of layers, and preferably, it can include a first liquid preparation step of preparing a first solution forming a first layer and a second liquid preparation step of preparing a second solution forming a second layer. Each solution forming a plurality of layers can be formed by mixing a polymer resin, an additive, and a solvent in a predetermined amount, and each layer can be formed by the first solution and the second solution prepared in the liquid preparation step (S100), thereby forming a plurality of layers.

[0131]

[0132] The first solution preparation step may include a step 1-1 in which dimethylacetamide (DMAC), polyvinyl pyrrolidone (PVP K30), and citric acid are mixed in predetermined amounts for a predetermined time, a step 1-2 in which deionized water (DW) is added to the solution prepared in the step 1-1 and the mixture is stirred for a predetermined time, a step 1-3 in which polysulfone is added and stirred for a predetermined time, and a step 1-4 in which the solution of the step 1-3 is vacuum-degassed for a predetermined time.

[0133] The above-determined content of the first solution may be a mixed solution containing, but is not limited to, 5 to 20 wt% of polysulfone, 65 to 80 wt% of dimethylacetamide, 5 to 15 wt% of polyvinyl pyrrolidone (PVP K30), 1 to 5 wt% of delonized water (DW), and 1 to 5 wt% of citric acid (CA), based on the total weight% of the first solution.

[0134] Preferably, the first solution may be a mixed solution containing 13.5 wt% of polysulfone, 63.3 wt% of dimethylacetamide, 9.5 wt% of polyvinyl pyrrolidone (PVP K30), 1.2 wt% of delonized water (DW), and 2.5 wt% of citric acid (CA).

[0135]

[0136] The second solution can be prepared by including a step 2-1 of adding dimethylacetamide (DMAC), polyvinyl pyrrolidone (PVP K30), and lactic acid (LA) and stirring for a predetermined time, a step 1-2 of adding ultrapure distilled water to the solution obtained through step 2-1 and stirring for a predetermined time, a step 2-3 of adding polysulfone to the solution obtained through step 2-2 and stirring for a predetermined time, a step 2-4 of adding polyethylene glycol after performing step 2-3 and stirring for a predetermined time, and a step 2-5 of vacuum defoaming the solution obtained through step 2-4 for a predetermined time.

[0137] The predetermined content of the second solution may be a mixed solution containing, but is not limited to, 5 to 20 wt% of polysulfone, 65 to 80 wt% of dimethylacetamide, 5 to 15 wt% of polyvinyl pyrrolidone (PVP K30), 1 to 10 wt% of polyethylene glycol, 1 to 5 wt% of delonized water (DW), and 1 to 1 wt% of lactic acid (LA), based on the total weight% of the second solution.

[0138] Preferably, the second solution may be a mixed solution containing 17 wt% of polysulfone, 68.85 wt% of dimethylacetamide, 7.45 wt% of polyvinyl pyrrolidone (PVP K30), 4 wt% of polyethylene glycol, 1.2 wt% of delonized water (DW), and 1.5 wt% of lactic acid (LA).

[0139]

[0140] In the above-described liquid preparation step, a plurality of the solutions prepared may be injected into a nozzle including a plurality of discharge ports so as to be injected from each of the discharge ports and injected into a coagulation tank. The nozzle may include two or more annular discharge ports arranged concentrically, and each of the solutions may be injected into each of the discharge ports so as to be injected. The first solution and the second solution may be injected into the coagulation tank from different discharge ports included in the nozzle so as to form a plurality of layers. Preferably, the temperature of the coagulation tank may be 55°C, but is not limited thereto.

[0141]

[0142] In the radiation step, the solution radiated into the coagulation tank undergoes a phase transition, and is then wound around a winding roll to form a hollow fiber membrane. Preferably, the winding speed of the winding roll can be 51 m / min, but is not limited thereto.

[0143]

[0144] The porous multilayer hollow fiber membrane manufactured by the method for manufacturing a porous multilayer hollow fiber membrane of the present invention can be formed to have a water permeability of 1,500 LMH or more, and the thickness of the membrane of the inner diameter side of the hollow membrane formed on the outer peripheral surface, i.e., the first layer, can be formed to be 150 µm to 250 µm, and the thickness of the membrane of the outer diameter side formed on the outer peripheral surface of the first layer, i.e., the second layer, can be formed to be 5 µm to 150 µm, and preferably, the first layer can be formed to be 200 µm, and the second layer can be formed to be 100 µm, but is not limited thereto. In addition, the porous multilayer hollow fiber membrane can be formed to have a pore size of 0.02 to 0.1 µm, and by forming a pore size of 0.02 to 0.1 µm in diameter, it can be manufactured to form a precision filtration membrane with excellent water permeability and remove viruses.

[0145]

[0146] <Example 1>

[0147] The present invention will be described in more detail based on examples. Methods for measuring various physical properties will be described below. Temperatures were all 25°C, except for those described. O It was done in C.

[0148] To prepare a first solution, 73.30 wt% of dimethylacetamide (DMAC), 9.5 wt% of polyvinyl pyrrolidone (PVP K30), and 2.5 wt% of citric acid were added relative to the total weight of the first solution, and stirring was performed for 3 hours. 1.2 wt% of deionized water (DW) was added to the solution, stirring was performed for 1 hour, and 13.5 wt% of polysulfone was added, stirring was performed for 8 hours, and vacuum degassing was performed for 4 hours to prepare a first solution.

[0149]

[0150] To prepare a second solution, 68.85 wt% of dimethylacetamide (DMAC), 7.45 wt% of polyvinyl pyrrolidone (PVP K30), and 1.5 wt% of lactic acid (LA) were added relative to the total weight of the second solution, and stirred for 3 hours. 1.2 wt% of ultrapure distilled water was added to the stirred solution, and stirred for 1 hour, and 17 wt% of polysulfone was added, and stirred for 8 hours. After the stirring, 4.0 wt% of polyethylene glycol was added, stirred for 3 hours, and then vacuum degassing was performed for 4 hours to prepare a second solution.

[0151]

[0152] <Example 2>

[0153] The first and second solutions manufactured in Example 1 were sprayed into a coagulation tank containing an internal coagulant composed of 95 wt% dimethylacetamide (DMAC) solvent and 5 wt% deionized water (DW), and wound with an immersion roll rotating at 30 rpm (51 m / min). More specifically, the internal coagulant includes an external coagulation tank spaced 15 cm apart, and the inside of the external coagulation tank contains water at 55°C. The results of the property evaluation of the obtained hollow fiber membrane are shown in Table 1 below.

[0154] OD / ID (㎛) Water flow rate (g / min) Flow rate (LMH) 630~712 / 331~42543.53871

[0155] Table 1 is a table showing the physical property evaluation of the porous multilayer hollow fiber membrane manufactured through the above-mentioned examples and the above-mentioned example 2. It was confirmed that the size ratio of the outer diameter to the inner diameter was 630~712 / 331~425㎛, the water permeability in the simple module was 43.5g / min, and the flow rate was 3871LMH.

[0156]

[0157] It should be understood that the embodiments of the present invention are not necessarily limited to the above-described embodiments, and that those skilled in the art will readily appreciate the possibility of various modifications and implementations within an equivalent scope. Therefore, the true scope of the present invention is defined by the claims set forth below.

Claims

1. Hollow; A first layer formed on the outer surface of the hollow body; and A porous multilayer hollow fiber membrane having a water permeability higher than a predetermined value and including a second layer formed on the outer surface of the first layer and capable of removing viruses.

2. In paragraph 1, The first layer is formed to a thickness of 150 μm to 250 μm, The second layer is a porous multilayer hollow membrane formed with a thickness of 5 μm to 150 μm.

3. In paragraph 1, The above-determined figure is 1,500LMH, a porous multilayer hollow membrane.

4. In paragraph 1, A porous multilayer hollow membrane formed with pores having a diameter of 0.02 to 0.1 μm.

5. In paragraph 1, The first layer and the second layer, A porous multilayer hollow fiber membrane formed by discharging a solution containing additives and polymer resin dissolved in a solvent into a non-solvent.

6. In paragraph 5, The above polymer resin is, A porous multilayer hollow fiber membrane comprising at least one of polysulfone, polyethersulfone, polyacrylonitrile, polyethylene, polyimide, polyamide, polyetherimide, cellulose acetate, and polyvinylidene fluoride.

7. In paragraph 5, Certain additives are, A porous multilayer hollow fiber membrane containing at least one of polyvinyl pyrrolidone (PVP K30), delonized water (DW), citric acid (CA), and lactic acid (LA).

8. In paragraph 5, The above solvent is, A porous multilayer hollow fiber membrane comprising at least one of 1-methyl-2-pyrrolidone, dimethylacetamide, and dimethylsulfoxide.

9. In paragraph 1, When the thickness of the second layer film is K and the thickness of the second layer film is L, And, A porous multilayer hollow fiber membrane that satisfies the following mathematical expression 1 when . [Mathematical Formula 1] (In the above mathematical formula, W is the water permeability, K is the thickness of the membrane of the second layer, L is the thickness of the membrane of the first layer, and the thickness of the hollow fiber membrane , is a constant that increases proportionally as water permeability increases) A porous multilayer hollow fiber membrane having a plurality of layers formed, including a first layer formed on the outer surface of the hollow body with a thickness of 10.200 μm and a second layer formed on the outer surface of the first layer with a thickness of 100 μm, and having a water permeability higher than a predetermined value and capable of removing viruses.

11. A step of preparing each solution to form multiple layers; A radiating step of radiating a plurality of the solutions prepared in the above liquefaction step into a nozzle including a plurality of circular discharge ports into a coagulation tank; and A method for manufacturing a porous multilayer hollow fiber membrane, comprising a winding step of winding the precipitate that has undergone a phase change in the above radiation step onto a winding roll.

12. In paragraph 11, The above step of the liquid phase is, A first solution preparation step for preparing a first solution to form a first layer according to predetermined steps; and A method for manufacturing a porous multilayer hollow fiber membrane, comprising a second solution preparation step of preparing a second solution to form a second layer according to predetermined steps.

13. In paragraph 11, The above solution is, A method for manufacturing a porous multilayer hollow fiber membrane, which is formed by dissolving an additive and a polymer resin in a predetermined amount in a solvent.

14. In paragraph 13, The above polymer resin is, A method for producing a porous multilayer hollow fiber membrane, comprising at least one of polysulfone, polyethersulfone, polyacrylonitrile, polyethylene, polyimide, polyamide, polyetherimide, cellulose acetate, and polyvinylidene fluoride.

15. In paragraph 13, The above additives are, A porous multilayer hollow fiber membrane containing at least one of polyvinyl pyrrolidone (PVP K30), delonized water (DW), citric acid (CA), and lactic acid (LA).

16. In paragraph 13, The above solvent is, A method for manufacturing a porous multilayer hollow fiber membrane, comprising at least one of 1-methyl-2-pyrrolidone, dimethylacetamide, and dimethylsulfoxide.

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