WO2015056853A1 - Membrane en fibres creuses poreuses à asymétrie en fluorure de polyvinylidène et son procédé de fabrication - Google Patents
Membrane en fibres creuses poreuses à asymétrie en fluorure de polyvinylidène et son procédé de fabrication Download PDFInfo
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- WO2015056853A1 WO2015056853A1 PCT/KR2014/002394 KR2014002394W WO2015056853A1 WO 2015056853 A1 WO2015056853 A1 WO 2015056853A1 KR 2014002394 W KR2014002394 W KR 2014002394W WO 2015056853 A1 WO2015056853 A1 WO 2015056853A1
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- Prior art keywords
- hollow fiber
- fiber membrane
- pvdf
- porous hollow
- asymmetric porous
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- 239000012528 membrane Substances 0.000 title claims abstract description 223
- 239000012510 hollow fiber Substances 0.000 title claims abstract description 216
- 239000002033 PVDF binder Substances 0.000 title claims abstract description 125
- 229920002981 polyvinylidene fluoride Polymers 0.000 title claims abstract description 125
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 26
- 239000011148 porous material Substances 0.000 claims abstract description 94
- 238000009987 spinning Methods 0.000 claims abstract description 83
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 50
- 238000000926 separation method Methods 0.000 claims abstract description 49
- 230000035699 permeability Effects 0.000 claims abstract description 32
- 239000002904 solvent Substances 0.000 claims description 80
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical group O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 claims description 35
- 239000011347 resin Substances 0.000 claims description 35
- 229920005989 resin Polymers 0.000 claims description 35
- 239000011550 stock solution Substances 0.000 claims description 32
- 239000000243 solution Substances 0.000 claims description 28
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 27
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 23
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 20
- URAYPUMNDPQOKB-UHFFFAOYSA-N triacetin Chemical compound CC(=O)OCC(OC(C)=O)COC(C)=O URAYPUMNDPQOKB-UHFFFAOYSA-N 0.000 claims description 20
- NIQCNGHVCWTJSM-UHFFFAOYSA-N Dimethyl phthalate Chemical compound COC(=O)C1=CC=CC=C1C(=O)OC NIQCNGHVCWTJSM-UHFFFAOYSA-N 0.000 claims description 18
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 18
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 claims description 18
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 claims description 18
- 239000000701 coagulant Substances 0.000 claims description 17
- DOIRQSBPFJWKBE-UHFFFAOYSA-N dibutyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCCCC DOIRQSBPFJWKBE-UHFFFAOYSA-N 0.000 claims description 16
- 239000007788 liquid Substances 0.000 claims description 16
- 239000002202 Polyethylene glycol Substances 0.000 claims description 14
- FLKPEMZONWLCSK-UHFFFAOYSA-N diethyl phthalate Chemical compound CCOC(=O)C1=CC=CC=C1C(=O)OCC FLKPEMZONWLCSK-UHFFFAOYSA-N 0.000 claims description 14
- 229920001223 polyethylene glycol Polymers 0.000 claims description 14
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 12
- 235000013773 glyceryl triacetate Nutrition 0.000 claims description 11
- 229960002622 triacetin Drugs 0.000 claims description 11
- 230000007717 exclusion Effects 0.000 claims description 10
- FBSAITBEAPNWJG-UHFFFAOYSA-N dimethyl phthalate Natural products CC(=O)OC1=CC=CC=C1OC(C)=O FBSAITBEAPNWJG-UHFFFAOYSA-N 0.000 claims description 9
- 229960001826 dimethylphthalate Drugs 0.000 claims description 9
- ARXJGSRGQADJSQ-UHFFFAOYSA-N 1-methoxypropan-2-ol Chemical compound COCC(C)O ARXJGSRGQADJSQ-UHFFFAOYSA-N 0.000 claims description 8
- MQIUGAXCHLFZKX-UHFFFAOYSA-N Di-n-octyl phthalate Natural products CCCCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCCCC MQIUGAXCHLFZKX-UHFFFAOYSA-N 0.000 claims description 8
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 claims description 8
- 230000001112 coagulating effect Effects 0.000 claims description 8
- MIMDHDXOBDPUQW-UHFFFAOYSA-N dioctyl decanedioate Chemical compound CCCCCCCCOC(=O)CCCCCCCCC(=O)OCCCCCCCC MIMDHDXOBDPUQW-UHFFFAOYSA-N 0.000 claims description 7
- 230000001133 acceleration Effects 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 5
- 239000004793 Polystyrene Substances 0.000 claims description 4
- 108010046685 Rho Factor Proteins 0.000 claims description 4
- 239000011324 bead Substances 0.000 claims description 4
- 239000004816 latex Substances 0.000 claims description 4
- 229920000126 latex Polymers 0.000 claims description 4
- 229920002223 polystyrene Polymers 0.000 claims description 4
- 239000000203 mixture Substances 0.000 abstract description 6
- 239000011800 void material Substances 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 15
- 238000005345 coagulation Methods 0.000 description 14
- 230000015271 coagulation Effects 0.000 description 14
- LZDKZFUFMNSQCJ-UHFFFAOYSA-N 1,2-diethoxyethane Chemical compound CCOCCOCC LZDKZFUFMNSQCJ-UHFFFAOYSA-N 0.000 description 8
- 238000002156 mixing Methods 0.000 description 8
- 238000002844 melting Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- BQCIDUSAKPWEOX-UHFFFAOYSA-N 1,1-Difluoroethene Chemical compound FC(F)=C BQCIDUSAKPWEOX-UHFFFAOYSA-N 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 229920001577 copolymer Polymers 0.000 description 6
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 238000005191 phase separation Methods 0.000 description 5
- 230000000704 physical effect Effects 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 229920001519 homopolymer Polymers 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 3
- 229920006373 Solef Polymers 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 229920002301 cellulose acetate Polymers 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 239000011737 fluorine Substances 0.000 description 3
- 229920001477 hydrophilic polymer Polymers 0.000 description 3
- -1 polyethylene Polymers 0.000 description 3
- YMMLWJCSQCRGHW-UHFFFAOYSA-N ClCCCCCl.F.F.F Chemical compound ClCCCCCl.F.F.F YMMLWJCSQCRGHW-UHFFFAOYSA-N 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- XMJIBINNJWGZKE-UHFFFAOYSA-N F.C(CF)F.C=C Chemical group F.C(CF)F.C=C XMJIBINNJWGZKE-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 102000007562 Serum Albumin Human genes 0.000 description 2
- 108010071390 Serum Albumin Proteins 0.000 description 2
- 239000005708 Sodium hypochlorite Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000008235 industrial water Substances 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 239000002861 polymer material Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000009966 trimming Methods 0.000 description 2
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 description 1
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 238000011001 backwashing Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000005194 fractionation Methods 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920006393 polyether sulfone Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0011—Casting solutions therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0013—Casting processes
- B01D67/00135—Air gap characteristics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
- B01D69/087—Details relating to the spinning process
- B01D69/088—Co-extrusion; Co-spinning
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/30—Polyalkenyl halides
- B01D71/32—Polyalkenyl halides containing fluorine atoms
- B01D71/34—Polyvinylidene fluoride
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/022—Asymmetric membranes
- B01D2325/0231—Dense layers being placed on the outer side of the cross-section
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/026—Sponge structure
Definitions
- the present invention relates to a method for producing a polyvinylidene fluoride (hereinafter, abbreviated as “PVDF”) asymmetric porous hollow fiber membrane, and more particularly, a fluorine-based material used for water treatment such as drainage treatment, water purification treatment, industrial water production, and the like. It relates to a hollow fiber membrane having an asymmetric-sponge structure using PVDF.
- PVDF polyvinylidene fluoride
- Membrane technology is an advanced separation technology that almost completely separates and removes the substance to be treated in the treated water according to the pore size, pore distribution, and surface charge of the membrane.
- the production of high-quality drinking water and industrial water Its application range is expanding, including sewage / wastewater treatment and recycling, and clean production processes related to the development of zero discharge systems. It is becoming one of the key technologies that will attract attention in the 21st century.
- the separation membrane for water treatment may be in the form of a hollow fiber membrane.
- a hollow fiber membrane is a membrane having a hollow ring shape, and has an advantage of increasing a membrane area per unit volume of a module compared to a flat membrane.
- air scrubbing is performed to remove the deposit by shaking the membrane by introducing a bubble into the backwashing or module to remove the deposit by passing the clean liquid in the direction opposite to the filtration direction as the cleaning method of the membrane. Etc. can be used effectively.
- Typical characteristics required for the hollow fiber membrane for water treatment include proper porosity (number of empty pores) for the purpose of separation efficiency, uniform pore distribution for the purpose of improving the fractionation accuracy, and separation of the object to be separated effectively. It is required to have an optimum pore size.
- material properties chemical resistance, chemical resistance, heat resistance, etc. to chemical treatment are required.
- Polymer materials used in the water treatment process using membrane technology include polysulfone, polyethersulfone and polyacrylonitrile, polyethylene, polypropylene, and cellulose acetate. non-fluorine materials such as actate) and polyvinylidene fluoride (hereinafter referred to as PVDF).
- PVDF polyvinylidene fluoride
- Publication No. KR 10-2003-0001474 discloses a symmetrical PVDF hollow fiber that is hydrophilized (EVA coated) on the surface of the hollow fiber membrane extruded using PVDF, an organic solvent and an inorganic fine powder.
- This is a desert, which has a problem in that the durability and the browning phenomenon due to the structural deformation of PVDF occurs in the process of extracting inorganic fine powder by loading in an alkaline solution, and additionally introduced a hydrophilization treatment process There is a problem of poor economics.
- Korean Patent Publication No. KR 10-2009-0026304 discloses a PVDF hollow fiber membrane prepared by spinning a PVDF crude liquid containing a cellulose acetate-based hydrophilic polymer and a PVDF crude liquid containing no hydrophilic polymer through a triple nozzle. This is because the cellulose acetate used as the hydrophilic polymer is weak to alkalis and / or acids, which causes disadvantages in the durability of the membrane during chemical washing during actual water treatment operation.
- Nonsolvent induced phase separation (NIPS) method (Publication No. KR 10-2011-0117781), which is a non-solvent manufacturing method of hollow fiber membranes, has various changes in spinning conditions to form various structures, particularly asymmetrical structures of membranes. It can be, it is easy to adjust the pore (Pore) size by adding a variety of additives, there is an advantage to obtain a high water permeability by giving a hydrophilization to the separator.
- PVDF hollow fiber membranes manufactured by the conventional NIPS method have a weak mechanical strength in general, and in particular, since the finger-like structure and the macro voids are generated inside the separator, the tensile strength is low. There was a problem that a breakage phenomenon of the separator occurs.
- the present invention has been made to solve the above problems, to prevent the formation of finger-like macro voids in the PVDF hollow fiber membrane to increase the tensile strength, the phenomenon of fracture of the membrane It is an object of the present invention to provide a PVDF asymmetric porous hollow fiber membrane and a method of manufacturing the same, while simultaneously preventing high water permeability and excellent rejection rate.
- the present invention relates to a method for producing a PVDF asymmetric porous hollow fiber membrane, preparing a spinning solution containing a polyvinylidene fluoride (PVDF) resin, a solvent and a non-solvent; And forming the hollow fiber by spinning the spinning solution through a spinning nozzle and immersing it in an external coagulant.
- the spinning may be performed under a specific back pressure ( ⁇ P).
- ⁇ P specific back pressure
- the solvent is gamma-butyrolactone ( ⁇ -butyrolactone), dimethylacetamide (DMAc), N-methyl-2- Pyrrolidone, dimethyl sulfoxide, dimethylformamide, Dibutyl Phthalate, Dimethyl phthalate, Diethyl phthalate, Dioctyl phthalate, Dioctyl sebacate And glycerol triacetate (Glycerol triacetate) may be characterized in that it comprises one or more selected from.
- the non-solvent comprises at least one selected from polyethylene glycol, ethylene glycol, propylene glycol, diethylene glycol and propylene glycol methyl ether It can be characterized by.
- the back pressure ( ⁇ P) may be characterized by satisfying the following equation (1).
- Equation 1 S (mm -3 ) is a value of the function L / (A ⁇ D 2 ), L (mm) is the length of the hole (hole) of the portion in which the crude liquid is discharged from the nozzle (nozzle) , D (mm) is the hole diameter, the total hole diameter minus the diameter of the internal coagulant hole, A (mm 2 ) is the hole cross-sectional area minus the cross-sectional area of the internal coagulant hole, and Q is the discharge amount (g / min), ⁇ is the viscosity of the spinning stock (poise at 25 ° C), ⁇ is the shape factor, ⁇ is the density of the PVDF resin (g / cm 3 ), g c is the gravitational acceleration (cm / sec 2 ) , H is the number of holes in the detention.
- PVDF asymmetric porous hollow fiber membrane comprises a hollow and a separation layer formed along the outer periphery of the separation layer, The inside is spherulite like structure, (Asymmetry structure) having a sponge like structure toward the outer surface, PVDF asymmetric porous hollow fiber membrane having a mean pore of 0.1 ⁇ 0.2 ⁇ m (Hereinafter, it is defined as the hollow fiber membrane 1).
- ⁇ of Equation 1 may be a rational number satisfying 2,000 ⁇ 7,000.
- p in Equation 1 in the method of manufacturing the hollow fiber membrane 1, may be a rational number satisfying 1.75 ⁇ ⁇ ⁇ 1.79.
- ⁇ of Equation 1 in the method of manufacturing the hollow fiber membrane 1, may be a rational number satisfying 23 ⁇ ⁇ ⁇ 24.
- S in the formula (1) may be characterized in that the rational number satisfying 40 ⁇ S ⁇ 70.
- Q in Equation 1 is a rational number satisfying 7 ⁇ Q ⁇ 20
- H is a rational number satisfying 1 ⁇ H ⁇ 10. It can be characterized by.
- the spinning solution is 60 to 200 parts by weight of solvent and 5 to 30 parts by weight of non-solvent based on 100 parts by weight of the PVDF resin. It may be characterized by including.
- PVDF asymmetric porous hollow fiber membrane (hollow fiber membrane 1) of the present invention prepared under such a manufacturing condition is hollow;
- the separation layer may be characterized in that the pores satisfying the error range ⁇ 60% of the average pore size are 80% or more of the total pores.
- the PVDF asymmetric porous hollow fiber membrane (hollow fiber membrane 1) of the present invention may have a water permeability of 1,000 LMH or more, and a rejection ratio for PLB (Polystyrene latex bead, average particle diameter of 0.1 ⁇ m) may be 90% or more.
- PLB Polystyrene latex bead, average particle diameter of 0.1 ⁇ m
- PVDF asymmetric porous hollow fiber membrane comprises a hollow and a separation layer formed along the outer periphery of the hollow
- the separation PVDF asymmetric porous hollow fiber membrane (hereinafter defined as hollow fiber membrane 2) having a form of asymmetry-sponge like structure and having an average pore of 0.02 to 0.1 ⁇ m or less in the separation layer can be prepared.
- ⁇ of Equation 1 may be a rational number satisfying 200 ⁇ ⁇ ⁇ 2,000.
- p in Equation 1 in the method of manufacturing the hollow fiber membrane 2, p in Equation 1 may be a rational number satisfying 1.75 ⁇ ⁇ ⁇ 1.79.
- ⁇ of Equation 1 in the method of manufacturing the hollow fiber membrane 2, ⁇ of Equation 1 may be a rational number satisfying 23 ⁇ ⁇ ⁇ 24.
- S in the formula (1) in the method of manufacturing the hollow fiber membrane 2, S in the formula (1) may be characterized in that the rational number satisfying 40 ⁇ S ⁇ 70.
- Q in Equation 1 is a rational number satisfying 7 ⁇ Q ⁇ 20
- H is a rational number satisfying 1 ⁇ H ⁇ 10. It can be characterized by.
- the spinning solution in the method of manufacturing the hollow fiber membrane 2 of the present invention, is 120 to 250 parts by weight of solvent and 20 to 80 parts by weight of non-solvent based on 100 parts by weight of the PVDF resin. It may be characterized by including.
- PVDF asymmetric porous hollow fiber membrane (hollow fiber membrane 2) of the present invention prepared under such a manufacturing condition is hollow;
- the separation layer may be characterized in that the pores satisfying the error range ⁇ 60% of the average pore size are 95% or more of the total pores.
- the PVDF asymmetric porous hollow fiber membrane (hollow fiber membrane 1) of the present invention may have a water permeability of 500 LMH or more, and an exclusion rate for PLB (Polystyrene latex bead, average particle diameter of 0.1 ⁇ m) may be 95% or more.
- PLB Polystyrene latex bead, average particle diameter of 0.1 ⁇ m
- PVDF asymmetric porous hollow fiber membrane of the present invention does not require an additional hydrophilization treatment process
- PVDF asymmetric porous hollow fiber membranes can be manufactured with high commerciality and economic feasibility. It is possible to increase the tensile strength by preventing the formation of finger-like macro voids at the same time, and to satisfy the high water permeability and the excellent rejection rate while preventing the occurrence of breakage of the separator.
- Back pressure control can provide a PVDF hollow fiber membrane having a specific structure.
- Figure 1 is a SEM measurement of the entire cross-section of the PVDF hollow fiber membrane prepared in Example 1.
- Figure 2 is a SEM measurement of the central cross-section of the PVDF hollow fiber membrane prepared in Example 1
- Figure 1 is an internal coagulant feed tube
- 2 is an outer tube
- 5 is a double tubular radial nozzle cross section.
- FIG. 3 is a cross-sectional view of a double tubular nozzle for producing a PVDF porous hollow fiber membrane used in Example 1.
- Figure 4 is a SEM measurement of the entire cross-section of the PVDF hollow fiber membrane prepared in Example 7.
- Figure 5 is a SEM measurement of the central cross section of the PVDF hollow fiber membrane prepared in Example 7.
- FIG. 6 is a cross-sectional photograph of a PVDF hollow fiber membrane prepared by a conventional NIPS method.
- asymmetry structure used in the present invention refers to a form in which a pore is continuously connected without a macrovoid on the cross section of a film and has a sponge shape.
- asymmetry-sponge like structure refers to a structure in which the entire cross section is dense than the inner cross section while the entire cross section forms a sponge structure, and the internal pores are larger than the external pores. It means.
- the present invention relates to a PVDF asymmetric porous hollow fiber membrane having two different forms through controlling the back pressure ( ⁇ P) of a spinning stock solution having a specific composition ratio.
- the PVDF asymmetric porous hollow fiber (hereinafter referred to as hollow fiber membrane 1) prepared by spinning under a back pressure ( ⁇ P) of 0.5 to 2 kg / cm 2 was hollow; And a separation layer formed along the outer circumference of the hollow, wherein the separation layer is an asymmetrical structure, and as shown in FIGS. 1 and 2, the inside is a spherical structure, and the sponge-like structure toward the outer surface. (Sponge like structure) and the internal and external structure may be characterized by having a different asymmetry structure (Asymmetry structure).
- the separation layer includes a spherical structure and a sponge structure, and the spherical structure tends to have a diameter gradient that gradually increases from the outer surface of the separation layer to the inner surface, and may serve as a support for the hollow fiber membrane.
- the average pore of the separation layer may be characterized in that 0.1 ⁇ 0.2 ⁇ m, preferably 0.1 ⁇ 0.15 ⁇ m.
- the separation layer may have a pore that satisfies the error range ⁇ 60% of the average pore size of 80% or more, preferably 90% or more, more preferably 93% or more of the total pores.
- PVDF asymmetric porous hollow fiber membrane of the present invention has excellent water permeability and BSA (bovin serum albumin) rejection rate, the water permeability may have more than 1,000 LMH, preferably 1,200 LMH or more.
- the exclusion rate for PLB Polystyrene latex bead, average particle diameter 0.1 ⁇ m
- PLB Polystyrene latex bead, average particle diameter 0.1 ⁇ m
- Hollow fiber membrane 1 of the present invention comprises the steps of preparing a spinning solution containing a polyvinylidene fluoride (PVDF) resin, a solvent and a non-solvent; And spinning the spinning stock solution through a spinning nozzle and immersing it in an external coagulating solution to form hollow fiber.
- PVDF polyvinylidene fluoride
- the step of feeding continuously stretching into the stretching machine containing the stretching solution may further include.
- the stretching solution may be ethylene glycol, glycerol, polyethylene glycol having a molecular weight of 400 or less, water, and the like, and may be stretched at a stretching ratio of 1.1 to 2.0 times at a stretching temperature of 15 ° C to 150 ° C. If the stretching temperature is less than 15 °C partial stretching occurs the hollow fiber membrane may not be uniformly stretched, if it exceeds 150 °C there is a disadvantage that the membrane shrinkage and cutting easily occur.
- the draw ratio is less than 1.1 times the length of the hollow yarns, the effect of the increase in co-operation and strength due to the draw is insufficient, and when the draw ratio exceeds 2.0 times, the film thickness decreases, which may cause a problem of weak mechanical properties.
- the polyvinylidene fluoride (PVDF) resin used in the production of the hollow fiber membrane 1 of the present invention is excellent in chemical resistance against sodium hypochlorite and the like, and has high heat resistance and high hydrophobicity, making it suitable for water treatment.
- the polyvinylidene fluoride used in the present invention may include vinylidene fluoride homopolymer and vinylidene fluoride copolymer.
- the vinylidene fluoride copolymer a copolymer of vinylidene fluoride with a monomer alone or in a mixed form, such as mono-fluoride ethylene, di-fluoride ethylene, tri-fluoride ethylene, ethylene chloride or ethylene, Can be used.
- Most preferably vinylidene fluoride homopolymer can be used.
- the PVDF resin preferably has a weight average molecular weight of 200,000 to 100 million. If the weight average molecular weight of the PVDF resin is less than 200,000, it may be difficult to form a hollow fiber due to the low viscosity, and if it exceeds 1000,000, moldability may be deteriorated due to high viscosity during melting.
- PVDF is mixed with a solvent and a non-solvent to make a spinning stock solution.
- the solvent is capable of dissolving 5 wt% or more of the PVDF resin even at a low temperature of 40 ° C. or lower, and raising the temperature to the melting point of the PVDF resin. Even if the solvent does not dissolve or swell the resin is defined as non-solvent.
- the solvent is gamma-butyrolactone, dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, dibutyl phthalate, dimethyl phthalate ( Dimethyl phthalate, diethyl phthalate, dioctyl phthalate, dioctylsebacate and glycerol triacetate may be used alone or in a mixed form, preferably gamma -Butyrolactone, dibutyl phthalate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, dioctyl sebacate and glycerol triacetate may be used alone or in a mixed form, more preferably gamma-butylolactone and glycerol Triacetate may be used singly or in mixed form.
- DMAc dimethylacetamide
- N-methyl-2-pyrrolidone N-methyl-2-pyrroli
- the amount of the solvent used may be 60 to 200 parts by weight of the solvent, preferably 80 to 180 parts by weight of the solvent, based on 100 parts by weight of the PVDF resin.
- the solvent when the solvent is less than 60 parts by weight based on 100 parts by weight of the PVDF resin, the PVDF resin does not dissolve well, and when it exceeds 200 parts by weight, the concentration of the PVDF resin is too low, the strength of the hollow fiber membrane is weakened, and the back pressure ⁇ P is increased. Lowered, there may be a problem that the spherical structure is not formed.
- the non-solvent may be a single or mixed form of polyethylene glycol, ethylene glycol, propylene glycol, diethylene glycol or propylene glycol methyl ether, the amount of the non-solvent 5 to 30 parts by weight based on 100 parts by weight of the PVDF resin, Preferably 5 to 20 parts by weight can be used.
- the non-solvent when the non-solvent is less than 5 parts by weight, the porosity and porosity of the hollow fiber membrane may be lowered, so that the water permeability may be lowered.
- the non-solvent is more than 30 parts by weight, the porosity increases, so that the water permeability increases but the removal rate may be lowered.
- the size may also be inconsistent and may be used within the above range.
- the mixing weight ratio of the solvent and the non-solvent is preferably 3: 1 to 5: 1, and the water permeability is increased by achieving high porosity and porosity when satisfying the mixing weight ratio range.
- the spinning stock solution may be prepared by mixing PVDF resin, solvent and non-solvent at 60 °C ⁇ 200 °C, when the temperature is less than 60 °C dissolution time of PVDF is consumed for a long time PVDF
- the inherent physical properties change, and if it exceeds 200 °C may change the structure of the polymer due to high heat may cause browning phenomenon it is good to mix within the above temperature range.
- the step of forming a hollow fiber is demonstrated.
- the step of forming the hollow fiber is to form the hollow fiber by spinning the spinning solution through a spinning nozzle and immersed in the external coagulation liquid, in which unlike the conventional PVDF hollow fiber membrane manufacturing method does not use an internal coagulant.
- the spinning nozzle may use a general spinning nozzle used in the art, and is not particularly limited. As an example, it is sectional drawing of the double tubular spinning nozzle 5 as shown in FIG.
- the spinning stock solution may be injected into the outer tube 2 of the double tubular spinning nozzle 5.
- the spinning nozzle is preferably maintained at 90 °C ⁇ 200 °C, if out of the temperature range may change the degree of crystallinity of the polymer may affect the porosity and strength of the hollow fiber membrane.
- the external coagulant is not particularly limited, but more preferably water, gamma butyrolactone ( ⁇ -butyrolactone), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl Formamide, Dibutyl Phthalate, Dimethyl Phthalate, Diethyl Phthalate, Dioctylphthalate, Dioctyl Sebacate, Glycerol Triacetate , Polyethylene glycol, ethylene glycol, propylene glycol, diethylene glycol, isopropyl alcohol, methanol or ethanol, or the like alone or in combination.
- the external coagulation solution may be -10 °C ⁇ 120 °C, preferably 10 °C ⁇ 80 °C. If the cooling rate in the external coagulating solution is slow, the spherical size inside the hollow fiber membrane may be large, and if the cooling rate is fast, the spherical size may be small.
- the cooling rate is too fast, so the water permeability can drop into too small spherical structure, if the temperature exceeds 120 °C, the cooling rate is too slow, the spherical size becomes too large as the phase separation is delayed The density and connection between each spherical structure is less, the porosity and tensile strength may be reduced.
- the solutions discharged from the spinning nozzle may control the micropore size and physical properties of the membrane by controlling the air gap to the external coagulating solution surface of the coagulation bath.
- the length of the preferred air gap may be 50 to 150 mm, more preferably 80 to 120 mm. At this time, if the distance from the discharged solution to the surface of the external coagulating solution of the coagulation bath is less than 50 mm, the distance is too close and solidification occurs at the nozzle part, which causes defects in the hollow fiber. Or eccentricity can occur.
- the spinning is preferably carried out under a back pressure ( ⁇ P) of 0.5 ⁇ 2kg / cm2, preferably under a back pressure ( ⁇ P) of 0.7 ⁇ 1.5kg / cm2, spinning at a back pressure less than 0.5kg / cm2 Spherical structure is not well formed in the separation layer, and an asymmetry-sponge like structure separation membrane is formed, and when it exceeds 2 kg / cm2, the outer selective layer becomes thick and the water permeability is increased. There may be a problem of decreasing.
- ⁇ P back pressure
- ⁇ P back pressure
- the said back pressure P can be calculated
- Equation 1 S (mm -3 ) is a value of the function L / (A ⁇ D 2 ), L (mm) is the length of the hole (hole) of the portion in which the crude liquid is discharged from the nozzle (nozzle) , D (mm) is the hole diameter (diameter of the total hole diameter internal coagulant hole), A (mm 2 ) is the hole cross-sectional area (cross-sectional area of the whole hole-cross-sectional area of the internal coagulant hole), Q is the discharge amount (g / min) , ⁇ is the viscosity of the spinning stock solution (poise at 25 °C), ⁇ is the form factor, ⁇ is the density of PVDF resin (g / cm 3 ), g c is the gravitational acceleration (cm / sec 2 ), H is The number of holes in the detention.
- ⁇ of Equation 1 is a rational number satisfying 2,000 ⁇ ⁇ ⁇ 7,000, preferably, a rational number satisfying 4,000 ⁇ ⁇ ⁇ 6,000, wherein when ⁇ is less than 2,000, the strength of the hollow fiber membrane becomes weak, The pressure ⁇ P may be too low, and when the pressure exceeds 7,000, the pore difference between the inside and the outside of the separator of the hollow fiber membrane may be too large.
- ⁇ of Equation 1 is a rational number satisfying 1.75 ⁇ ⁇ ⁇ 1.79, preferably a rational number satisfying 1.76 ⁇ ⁇ ⁇ 1.77, and ⁇ satisfying the above value in terms of sponge structure formation. It is advantageous.
- ⁇ of Equation 1 is preferably a rational number satisfying 23 ⁇ ⁇ ⁇ 24, preferably 23.4 ⁇ ⁇ ⁇ 23.8, and satisfying the above value of ⁇ forms a constant appearance and thickness of the hollow fiber membrane. In terms of advantages.
- S in Equation 1 may be a rational number satisfying 40 ⁇ S ⁇ 70, preferably a rational number satisfying 50 ⁇ S ⁇ 68, and when S is less than 40, retention of the flow of the detention inner bath liquid occurs. This may be a non-uniform and thus there may be a problem that the hollow fiber membrane single yarn phenomenon occurs, and if it exceeds 70 there may be a problem that the cross section of the hollow fiber membrane.
- Q in Equation 1 may be a rational number satisfying 7 ⁇ Q ⁇ 20, preferably 9 ⁇ Q ⁇ 18, and when Q is less than 7, the back pressure is lowered, resulting in radiation trimming and poor quality. There may be a problem, and if it exceeds 20, a die swell (DIE SWELL, a phenomenon in which the crude liquid swells and thins again at the discharge port, becomes uneven) may occur.
- DIE SWELL die swell
- the PVDF asymmetric porous hollow fiber membrane of the present invention can produce a PVDF asymmetric porous hollow fiber membrane with high commerciality and economic efficiency as described above, and the spherical outer side of the hollow fiber membrane has a sponge-like asymmetry structure (Asymmetry like structure) ), And can have excellent tensile strength while having excellent water permeability and rejection at the same time.
- the present invention can produce a hollow fiber membrane having a separation membrane of a different type from the hollow fiber membrane 1 described above by spinning under a condition different from the hollow fiber membrane 1 and a spinning solution and back pressure ( ⁇ P).
- the PVDF asymmetric porous hollow fiber membrane (hereinafter referred to as hollow fiber membrane 2) prepared by spinning under a back pressure ( ⁇ P) of 0.05 to 0.5 kg / cm 2 is formed along the outer periphery of the hollow and the hollow. 4 and 5, the separation layer may have the form of an asymmetry-sponge like structure. That is, unlike the hollow fiber membrane 1, the hollow fiber membrane 2 does not have a spherical structure layer.
- the separation layer forms an asymmetric-sponge structure in which no fingerlike macro voids exist, and the average pore of the separation layer is 0.1 ⁇ m or less, preferably 0.02 to 0.1 micrometer, More preferably, it can be characterized by being 0.02-0.8 micrometer.
- the separation layer may have a pore that satisfies the error range ⁇ 60% of the average pore size of 95% or more, preferably 97% or more of the total pores.
- PVDF asymmetric porous hollow fiber membrane of the present invention has excellent water permeability and BSA (bovin serum albumin) rejection rate
- the water permeability may have 500 LMH or more, preferably 580 LMH or more.
- the BSA exclusion rate may have 95% or more, preferably 97% or more.
- PVDF asymmetric porous hollow fiber membrane of the present invention comprises the steps of preparing a spinning stock solution containing a polyvinylidene fluoride (PVDF) resin, a solvent and a non-solvent; And spinning the spinning stock solution through a spinning nozzle and immersing it in an external coagulation solution to form hollow fibers.
- PVDF polyvinylidene fluoride
- the polyvinylidene fluoride (PVDF) resin used in the hollow fiber membrane production of the present invention is excellent in chemical resistance against sodium hypochlorite and the like, and has high heat resistance and high hydrophobicity, so that it is suitable for water treatment.
- the polyvinylidene fluoride used in the present invention may include vinylidene fluoride homopolymer and vinylidene fluoride copolymer.
- the vinylidene fluoride copolymer a copolymer of vinylidene fluoride with a monomer alone or in a mixed form, such as mono-fluoride ethylene, di-fluoride ethylene, tri-fluoride ethylene, ethylene chloride or ethylene, Can be used.
- Most preferably vinylidene fluoride homopolymer can be used.
- the PVDF resin is preferably a weight average molecular weight of 200,000 ⁇ 1,000,000. If the weight average molecular weight of the PVDF resin is less than 200,000, it may be difficult to form a hollow fiber due to the low viscosity, and if it exceeds 1,000,000, moldability may be deteriorated due to high viscosity during melting.
- PVDF is mixed with a solvent and a non-solvent to make a spinning stock solution.
- the solvent is capable of dissolving 5 wt% or more of the PVDF resin even at a low temperature of 40 ° C. or lower, and raising the temperature to the melting point of the PVDF resin. Even if the solvent does not dissolve or swell the resin is defined as non-solvent.
- the solvent is gamma-butyrolactone, dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, dibutyl phthalate, dimethyl phthalate ( Dimethyl phthalate, diethyl phthalate, dioctyl phthalate, dioctylsebacate and glycerol triacetate may be used alone or in combination.
- the solvent may be used in an amount of 120 to 250 parts by weight, preferably 140 to 220 parts by weight, based on 100 parts by weight of the PVDF resin.
- the non-solvent may be a single or mixed form of polyethylene glycol, ethylene glycol, propylene glycol, diethylene glycol or propylene glycol methyl ether, and the amount of the non-solvent is 20 to 80 parts by weight, preferably 100 parts by weight of the PVDF resin. Preferably 20 to 60 parts by weight. In this case, when the non-solvent is less than 20 parts by weight, the porosity and porosity of the hollow fiber membrane may be lowered, so that the water permeability may be lowered. When the non-solvent is more than 80 parts by weight, the pore size of the asymmetric sponge structure may be too uneven. It is good to use within the said range.
- the mixing weight ratio of the solvent and the non-solvent is preferably 3: 1 to 5: 1, and the water permeability is increased by achieving high porosity and porosity when the mixing weight ratio range is satisfied.
- the spinning stock solution may be prepared by mixing PVDF resin, a solvent and a non-solvent at 60 ° C. to 170 ° C., in which case the dissolution time of PVDF is consumed for a long time when the temperature is less than 60 ° C.
- the inherent physical properties change and if it exceeds 170 °C may change the structure of the polymer due to high heat may be browning phenomenon may be mixed within the above temperature range.
- the step of forming the hollow fiber is spinning the spinning stock solution through the spinning nozzle and immersed in the external coagulation liquid to form the hollow fiber
- the internal coagulant may be used alone or mixed with a solvent or a non-solvent.
- the solvent that can be used for the internal coagulant may be used at least one selected from dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and gamma butyrolactone (GBL),
- DMAc dimethylacetamide
- NMP N-methyl-2-pyrrolidone
- GBL gamma butyrolactone
- the non-solvent one or more of glycerin, ethyl glycol, diethyl glycol, and polyethylene glycol can be used.
- the mixing ratio in the case of mixing and using the solvent and the non-solvent as the internal coagulant may be used in a solvent: non-solvent ratio of 1: 9 to 7: 3 by weight, preferably in a 2: 8 to 6: 4 weight ratio.
- the spinning nozzle may use a general spinning nozzle used in the art, and is not particularly limited. As an example, it is sectional drawing of the double tubular spinning nozzle 5 as shown in FIG.
- the spinning stock solution may be injected into the outer tube 2 of the double tubular spinning nozzle 5.
- the spinning nozzle is preferably maintained at 90 °C ⁇ 200 °C, if out of the temperature range may change the degree of crystallinity of the polymer may affect the porosity and strength of the hollow fiber membrane.
- the external coagulant is not particularly limited, but more preferably water, gamma butyrolactone ( ⁇ -butyrolactone), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl Formamide, Dibutyl Phthalate, Dimethyl Phthalate, Diethyl Phthalate, Dioctylphthalate, Dioctyl Sebacate, Glycerol Triacetate , Polyethylene glycol, ethylene glycol, propylene glycol, diethylene glycol, isopropyl alcohol, methanol or ethanol, or the like alone or in combination.
- the solutions discharged from the spinning nozzle may control the micropore size and physical properties of the membrane by controlling the air gap to the external coagulating solution surface of the coagulation bath.
- Preferred lengths of the air gap may be 50 mm to 150 mm, more preferably 80 to 120 mm.
- the spinning is preferably performed under a back pressure ( ⁇ P) of 0.05 ⁇ 0.5 kg / cm2, preferably under a back pressure ( ⁇ P) of 0.1 ⁇ 0.4 kg / cm2, spinning at a back pressure of less than 0.05 kg / cm2
- ⁇ P back pressure
- ⁇ P back pressure
- the defect of the product is increased, if the content exceeds 0.5 kg / cm2, the hollow diameter of the hollow fiber membrane is not constant, There may be a problem that the deviation is severe and the water permeability is low.
- the back pressure ( ⁇ P) can be obtained through the following equation (1).
- Equation 1 S (mm -3 ) is a value of the function L / (A ⁇ D 2 ), L (mm) is the length of the hole (hole) of the portion in which the crude liquid is discharged from the nozzle (nozzle) , D (mm) is the hole diameter (diameter of the total hole diameter internal coagulant hole), A (mm 2 ) is the hole cross-sectional area (cross-sectional area of the whole hole-cross-sectional area of the internal coagulant hole), Q is the discharge amount (g / min) , ⁇ is the viscosity of the spinning stock solution (poise at 25 °C), ⁇ is the form factor, ⁇ is the density of PVDF resin (g / cm 3 ), g c is the gravitational acceleration (cm / sec 2 ), H is The number of holes in the detention.
- ⁇ of Equation 1 is a rational number satisfying 200 ⁇ ⁇ ⁇ 2,000, preferably a rational number satisfying 400 ⁇ ⁇ ⁇ 1,500, and in this case, when ⁇ is less than 200, the strength of the hollow fiber membrane may be weakened. And, if it exceeds 2,000, there may be a problem that the pore difference between the inside and outside the membrane of the hollow fiber membrane is too large.
- ⁇ of Equation 1 is a rational number that satisfies 1.75 ⁇ ⁇ ⁇ 1.79, preferably a rational number that satisfies 1.76 ⁇ ⁇ ⁇ 1.77, and ⁇ satisfies the above value in terms of sponge structure formation. It is advantageous.
- ⁇ of Equation 1 is preferably a rational number satisfying 23 ⁇ ⁇ ⁇ 24, preferably 23.4 ⁇ ⁇ ⁇ 23.8, and satisfying the above value of ⁇ forms a constant appearance and thickness of the hollow fiber membrane. In terms of advantages.
- S in Equation 1 may be a rational number satisfying 40 ⁇ S ⁇ 70, preferably a rational number satisfying 50 ⁇ S ⁇ 68, and when S is less than 40, retention of the flow of the detention inner bath liquid occurs. This may be a non-uniform and thus there may be a problem that the hollow fiber membrane single yarn phenomenon occurs, if it exceeds 70 there may be a non-uniform problem of the cross section of the hollow fiber membrane.
- Q in Equation 1 may be a rational number satisfying 7 ⁇ Q ⁇ 20, preferably 9 ⁇ Q ⁇ 18, and when Q is less than 7, the back pressure is lowered, resulting in radiation trimming and poor quality. There may be a problem, and if it exceeds 20, a die swell (DIE SWELL, a phenomenon in which the crude liquid swells and thins again in the discharge port, becomes uneven) may occur.
- DIE SWELL die swell
- the PVDF asymmetric porous hollow fiber membrane (hollow fiber membrane 1) of the present invention prepared in this manner can produce a PVDF asymmetric porous hollow fiber membrane with high commerciality and economy as described above, and has an asymmetry-sponge like structure. ) And excellent tensile strength while having excellent water permeability and rejection at the same time.
- the transfer was carried out by removing the air bubbles contained in the spinning stock solution using a vacuum pump, and then transferred to a double nozzle using a gear pump.
- the height (Air gap) of the nozzle and the coagulation bath surface was maintained at 10 cm.
- the mixed liquid thus discharged was cooled through a coagulation bath to induce phase separation.
- the mixed solution was wound up in a 25 ° C. water bath at a rate of 20 m / min.
- the manufactured hollow fiber membrane was found to have an asymmetric structure of an inner spherical structure and an outer sponge structure having an average pore of 0.1 ⁇ m, and satisfy an error range of 60% with an average diameter of 0.1 ⁇ m of 0.07 to The pores of 0.16 ⁇ were 80% of the total pores.
- Equation 1 S is 65 mm 2 , Q is 16 g / min, ⁇ is 6,000 (poise at melting temperature), ⁇ is 23.6, ⁇ is 1.78 g / cm 3 , and g c is gravity Acceleration (cm / sec 2 ) and H is 1.
- a hollow fiber membrane prepared in the same manner as in Example 1 was prepared, but the discharge amount (Q in Equation 1) was reduced in Equation 1, and the spinning stock solution was transferred and discharged to a double nozzle having a back pressure of 0.8 kg / cm 2.
- a hollow fiber membrane having an asymmetric structure having an average pore of 0.12 ⁇ m was prepared.
- the hollow fiber membrane had pores satisfying an error range of 60% with an average pore of 0.12 ⁇ m of 83% of the total pores.
- a hollow fiber membrane (hollow fiber membrane 1) manufactured in the same manner as in Example 1 was prepared, but by increasing the discharge amount (Q in Equation 1) in Equation 1, spinning with a double nozzle that maintains the back pressure 1.8 kg / cm2 By transferring and discharging the stock solution, a hollow fiber membrane having an asymmetric structure having an average pore of 0.13 ⁇ m was prepared. In addition, the hollow fiber membrane was 84% of the total pores satisfying the 60% error range of the average pore 0.13 ⁇ m.
- a hollow fiber membrane (hollow fiber membrane 1) prepared in the same manner as in Example 1 was prepared, but 100 parts by weight of gamma butyrolactone (GBL, solubility: 26.2 MPa 1/2 ) as a solvent and 20 parts by weight of diethyl glycol as nonsolvents Part and 5 parts by weight of polyethylene glycol were prepared, and a hollow fiber membrane having an asymmetric structure having an average pore of 0.11 ⁇ m was prepared using the same.
- GBL gamma butyrolactone
- a hollow fiber membrane (hollow fiber membrane 1) was prepared in the same manner as in Example 1, but 150 parts by weight of gamma butyrolactone (GBL, solubility: 26.2 MPa 1/2 ) as a solvent, 10 parts by weight of diethyl glycol as a non-solvent, and 10 parts by weight of polyethylene glycol was used to prepare a hollow fiber membrane having an asymmetric structure having an average pore of 0.14 ⁇ m.
- the hollow fiber membrane was 90.3% of the total pores satisfying the error range 60% of the average pore 0.14 ⁇ m.
- a hollow fiber membrane (hollow fiber membrane 1) was prepared in the same manner as in Example 1, but a hollow fiber membrane having an asymmetric-sponge structure having an average pore of 0.16 ⁇ m was prepared using a solvent of GTA (Glycerin triacetate) instead of DMAc.
- GTA Glycerin triacetate
- the hollow fiber membrane was 88.2% of the pores satisfying the error range 60% of the average pore 0.16 ⁇ m.
- the transfer was carried out by removing the air bubbles contained in the spinning stock solution using a vacuum pump, and then transferred to a double nozzle using a gear pump.
- the height (Air gap) of the nozzle and the coagulation bath surface was maintained at 10 cm.
- the mixed liquid thus discharged was cooled through a coagulation bath to induce phase separation.
- the mixed solution was wound up in a 25 ° C. water bath at a rate of 20 m / min.
- the manufactured hollow fiber membrane 2 was found to have an asymmetric-sponge structure having an average pore of 0.05 ⁇ m, and the pores satisfying the error range of 60% having an average pore diameter of 0.05 ⁇ m were 97% of the total pore. It was.
- Equation 1 S is 65 mm -3 , Q is 16 g / min, ⁇ is 50 (poise at 25 ° C), ⁇ is 23.6, ⁇ is 1.78 g / cm 3 , g c Is the acceleration of gravity (cm / sec 2 ) and H is 1.
- the hollow fiber membrane (hollow fiber membrane 2) manufactured in the same manner as in Example 1 was prepared, but by increasing the discharge amount (Q in Formula 1) in Equation 1, the back pressure is maintained in 0.4 kg / cm2 with a double nozzle
- the spinning stock solution was transferred and discharged to prepare a hollow fiber membrane having an asymmetric-sponge structure having an average pore of 0.04 ⁇ m.
- the hollow fiber membrane was 96.5% of the total pores satisfying the error range 60% of the average pore 0.04 ⁇ m.
- the hollow fiber membrane (hollow fiber membrane 2) manufactured in the same manner as in Example 1 was prepared, but by reducing the discharge amount (Q in Formula 1) in Equation 1, the back pressure is maintained as a double nozzle 0.15 kg / cm2
- the spinning stock solution was transferred and discharged to prepare a hollow fiber membrane having an asymmetric-sponge structure having an average pore of 0.07 ⁇ m.
- the hollow fiber membrane was 97.3% of the total pores satisfying the error range 60% of the average pore 0.07 ⁇ m.
- a hollow fiber membrane (hollow fiber membrane 2) prepared in the same manner as in Example 1 was prepared, but after preparing a spinning stock solution using 150 parts by weight of dimethylacetamide (DMAc, solubility: 22.7 MPa 1/2 ) as a solvent, To prepare a hollow fiber membrane having an asymmetric-sponge structure having an average pore size of 0.04 ⁇ m. In addition, the hollow fiber membrane was 98.1% of the total pores satisfying the error range 60% of the average pore 0.04 ⁇ m.
- DMAc dimethylacetamide
- a hollow fiber membrane (hollow fiber membrane 2) was prepared in the same manner as in Example 1, with 220 parts by weight of DMAc (solubility: 22.7 MPa 1/2 ) as a solvent, 35 parts by weight of diethyl glycol and 15 parts by weight of polyethylene glycol. Using this, a hollow fiber membrane having an asymmetric-sponge structure having an average pore size of 0.05 ⁇ m was prepared. In addition, the hollow fiber membrane was 96.9% of the total pores satisfying the 60% error range of the average pore 0.05 ⁇ m.
- a hollow fiber membrane (hollow fiber membrane 2) was prepared in the same manner as in Example 1, but using an NMP (N-methyl-2-pyrrolidone) instead of DMAc as a solvent to form an asymmetric sponge structure having an average pore size of 0.06 ⁇ m. Desert was prepared.
- the hollow fiber membrane was 98.2% of the pores satisfying the error range 60% of the average pore 0.06 ⁇ m.
- the mixed liquid thus discharged was cooled through a coagulation bath to induce phase separation, and then was wound up in a 25 ° C. water bath at a speed of 20 m / min.
- the hollow fiber membrane thus prepared had finger-like pores having a short axis of about 100 ⁇ m and a long axis of about 200 ⁇ m as shown in FIG. 6.
- a hollow fiber membrane (hollow fiber membrane 1) prepared in the same manner as in Example 1 was prepared, but 40 parts by weight of gamma butyrolactone (GBL, solubility: 26.2 MPa 1/2 ) as a solvent and 30 parts by weight of diethyl glycol as nonsolvents Part and 30 parts by weight of polyethylene glycol to prepare a spinning dope, which was used.
- the back pressure was 1.2 kg / cm 2.
- the hollow fiber membrane having the prepared asymmetric-sponge structure had an average pore of 0.22 ⁇ m, and the pores satisfying the error range of 60% of the average pore of 0.22 ⁇ m were 70.5% of the total pore.
- the hollow fiber membrane (hollow fiber membrane 2) prepared in the same manner as in Example 6, but by increasing the discharge amount (Q in Formula 1) in Equation 1, the back pressure is maintained in a double nozzle 0.6 kg / cm2
- the spinning stock solution was transferred and discharged to prepare a hollow fiber membrane having an asymmetric-sponge structure having an average pore of 0.04 ⁇ m.
- the hollow fiber membrane was 92.5% of the total pore pores satisfying the error range of 60% of the average pore 0.04 ⁇ m
- the hollow fiber membrane of Comparative Example 2 has a back pressure of more than 0.5 kg / cm2 the hollow diameter of the hollow fiber membrane It seems to be inconsistent.
- a hollow fiber membrane (hollow fiber membrane 2) prepared in the same manner as in Example 6 was prepared, but using the same PVDF and non-solvent, 300 wt% of dimethylacetamide (DMAc, solubility: 22.7 MPa 1/2 ) as a solvent After preparing the unused spinning stock solution, it was used, and the back pressure was 0.04 kg / cm 2.
- the hollow fiber membrane having the prepared asymmetric-sponge structure had an average pore of 0.07 ⁇ m, and the pores satisfying the error range of 60% of the average pore of 0.07 ⁇ m were 88.2% of the total pore.
- pure water at room temperature was supplied to one side of the module by DEAD-END method at 1.0 atm, and after measuring the amount of permeated water, the unit time, unit membrane area, It was converted into permeation amount per unit pressure.
- PLB average particle diameter: 0.1 ⁇ m, MagsphereInc
- An aqueous solution was supplied to one side of the manufactured hollow fiber membrane module at a pressure of 1.0 kg / cm 2 , and the concentration of PLB dissolved in the aqueous solution and the initially supplied raw water was measured using an ultraviolet spectrometer (Varian), Cary-100. Measured.
- the PLB exclusion rate was determined by converting the relative ratio of the absorption peaks measured at the wavelength of 275 nm as a percentage using Equation 2 below.
- Exclusion rate (%) (stock concentration-permeate concentration) / stock concentration ⁇ 100
- Tensile strength, tensile elongation, and the like of the hollow fiber membranes prepared by the tensile tester were measured.
- the tensile test was carried out at 23 ° C. with a gripping distance of 10 cm and a crosshead speed of 3 cm / min.
- a tensile tester (“RTM-100" manufactured by Toyo Baldwin Co., Ltd.)
- the measurement was performed under conditions of an initial sample length of 100 mm and a crosshead speed of 200 mm / min in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%.
- Example 1 Table 1 division Pure Permeability (LMH) PLB Exclusion Rate (%) Tensile Strength (MPa) Example 1 1,255 93.8 10.0 Example 2 1,385 92.5 9.8 Example 3 1,011 91.6 10.5 Example 4 1,000 94.2 11.2 Example 5 1,310 95.4 10.3 Example 6 1,490 90.8 9.2 Example 7 600 97.0 6.0 Example 8 510 98.0 6.5 Example 9 700 95.0 5.8 Example 10 400 98.3 7.8 Example 11 590 96.4 5.8 Example 12 610 94.0 5.5 Comparative Example 1 780 92.0 2.0 Comparative Example 2 1,710 84.3 3.9 Comparative Example 3 310 92.5 7.4 Comparative Example 4 745 91.0 3.8
- Comparative Example 1 the tensile strength was not good, the amount of solvent used was less than 50 parts by weight, and in Comparative Example 2 using an excessive amount of nonsolvent, the water permeability was very good, but the average porosity was too large and the porosity was uneven The PLB exclusion rate was lower than 85%, and the tensile strength was also poor.
- Comparative Example 3 although the back pressure was increased, it was confirmed that the pure permeability significantly deteriorated when compared with Examples 1 to 12, in particular, compared with Examples 1 to 6, Through this, it could be confirmed that the asymmetric porous hollow fiber membrane having excellent physical properties by simply adjusting the back pressure is not only an important factor but also a composition ratio of the spinning solution. As a result, the results of Comparative Example 2 were found to be similarly related to the composition ratio of the spinning stock solution with the back pressure.
- the PVDF asymmetric porous hollow fiber prepared by the specific method under the specific conditions suggested by the present invention was confirmed that no macropores in the form of fingers were produced.
- the present invention was confirmed to have excellent water permeability, BSA rejection rate and tensile strength.
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Artificial Filaments (AREA)
Abstract
La présente invention concerne une membrane en fibres creuses poreuse à asymétrie en PVDF et un procédé de fabrication de celle-ci et, plus particulièrement, un procédé de fabrication d'une membrane en fibres creuses poreuse possédant une structure asymétrique caractérisée en ce que l'intérieur d'une membrane de séparation possède une structure sphérique et l'extérieur de celle-ci possède une structure en éponge ou une membrane en fibres creuses poreuse possédant une membrane de séparation possédant une structure en éponge asymétrique en ajustant le rapport de composition et la pression de face arrière d'une solution de dopage de filage. De tels deux types de membranes en fibres creuses selon la présente invention correspondent à une membrane de séparation poreuse en fibre creuses en PVDF qui empêche un espace vide macroscopique de type doigt d'être généré à l'intérieur de la membrane de séparation poreuse en fibres creuses en PVDF, présente une excellente résistance à la traction, empêche un phénomène de fracture de la membrane de séparation, et ne bouche pas un pore sur la surface externe de la membrane de séparation, ce qui satisfait simultanément la perméabilité élevée à l'eau.
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KR1020130124600A KR101397842B1 (ko) | 2013-10-18 | 2013-10-18 | 폴리비닐덴플루오라이드 비대칭 다공성 중공사막 및 이의 제조방법 |
KR10-2013-0124600 | 2013-10-18 | ||
KR1020130138240A KR101401160B1 (ko) | 2013-11-14 | 2013-11-14 | 폴리비닐덴플루오라이드 비대칭 다공성 중공사막 및 이의 제조방법 |
KR10-2013-0138240 | 2013-11-14 |
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PCT/KR2014/002394 WO2015056853A1 (fr) | 2013-10-18 | 2014-03-21 | Membrane en fibres creuses poreuses à asymétrie en fluorure de polyvinylidène et son procédé de fabrication |
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CN111690167A (zh) * | 2020-06-19 | 2020-09-22 | 山西汾西重工有限责任公司 | 一种析出成型装置及方法 |
CN115337798A (zh) * | 2022-07-15 | 2022-11-15 | 上海工程技术大学 | 具有稳定晶型的大孔径pvdf中空纤维膜及其制备方法 |
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