JPH04250834A - Precision filter membrane - Google Patents
Precision filter membraneInfo
- Publication number
- JPH04250834A JPH04250834A JP1037791A JP1037791A JPH04250834A JP H04250834 A JPH04250834 A JP H04250834A JP 1037791 A JP1037791 A JP 1037791A JP 1037791 A JP1037791 A JP 1037791A JP H04250834 A JPH04250834 A JP H04250834A
- Authority
- JP
- Japan
- Prior art keywords
- membrane
- filtration
- cellulose acetate
- pore diameter
- acetylation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000012528 membrane Substances 0.000 title claims abstract description 91
- 238000001914 filtration Methods 0.000 claims abstract description 50
- 229920002301 cellulose acetate Polymers 0.000 claims abstract description 29
- 239000011148 porous material Substances 0.000 claims abstract description 27
- 230000021736 acetylation Effects 0.000 claims abstract description 14
- 238000006640 acetylation reaction Methods 0.000 claims abstract description 14
- 230000007423 decrease Effects 0.000 claims abstract description 7
- 239000003513 alkali Substances 0.000 claims abstract description 6
- 238000001471 micro-filtration Methods 0.000 claims description 16
- 238000009295 crossflow filtration Methods 0.000 claims description 8
- 239000012982 microporous membrane Substances 0.000 claims 1
- 239000002344 surface layer Substances 0.000 abstract description 8
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 238000000151 deposition Methods 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 30
- 239000012530 fluid Substances 0.000 description 26
- 239000002904 solvent Substances 0.000 description 26
- 230000004907 flux Effects 0.000 description 22
- 238000000034 method Methods 0.000 description 20
- 238000011001 backwashing Methods 0.000 description 14
- 239000000243 solution Substances 0.000 description 12
- 239000010419 fine particle Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000012466 permeate Substances 0.000 description 9
- 238000001035 drying Methods 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 238000000926 separation method Methods 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 6
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 239000000725 suspension Substances 0.000 description 6
- 238000000108 ultra-filtration Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 230000001580 bacterial effect Effects 0.000 description 5
- 238000009835 boiling Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 4
- -1 alcohol sulfates Chemical class 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 239000004627 regenerated cellulose Substances 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000007127 saponification reaction Methods 0.000 description 3
- CXWXQJXEFPUFDZ-UHFFFAOYSA-N tetralin Chemical compound C1=CC=C2CCCCC2=C1 CXWXQJXEFPUFDZ-UHFFFAOYSA-N 0.000 description 3
- QPFMBZIOSGYJDE-UHFFFAOYSA-N 1,1,2,2-tetrachloroethane Chemical compound ClC(Cl)C(Cl)Cl QPFMBZIOSGYJDE-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- ZHNUHDYFZUAESO-UHFFFAOYSA-N Formamide Chemical compound NC=O ZHNUHDYFZUAESO-UHFFFAOYSA-N 0.000 description 2
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- 239000000020 Nitrocellulose Substances 0.000 description 2
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- FJWGYAHXMCUOOM-QHOUIDNNSA-N [(2s,3r,4s,5r,6r)-2-[(2r,3r,4s,5r,6s)-4,5-dinitrooxy-2-(nitrooxymethyl)-6-[(2r,3r,4s,5r,6s)-4,5,6-trinitrooxy-2-(nitrooxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-3,5-dinitrooxy-6-(nitrooxymethyl)oxan-4-yl] nitrate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O)O[C@H]1[C@@H]([C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@@H](CO[N+]([O-])=O)O1)O[N+]([O-])=O)CO[N+](=O)[O-])[C@@H]1[C@@H](CO[N+]([O-])=O)O[C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O FJWGYAHXMCUOOM-QHOUIDNNSA-N 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 238000005119 centrifugation Methods 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 2
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 150000002170 ethers Chemical class 0.000 description 2
- 238000000855 fermentation Methods 0.000 description 2
- 230000004151 fermentation Effects 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- TZIHFWKZFHZASV-UHFFFAOYSA-N methyl formate Chemical compound COC=O TZIHFWKZFHZASV-UHFFFAOYSA-N 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 229920001220 nitrocellulos Polymers 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002985 plastic film Substances 0.000 description 2
- 229920006255 plastic film Polymers 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 2
- 102000004169 proteins and genes Human genes 0.000 description 2
- 108090000623 proteins and genes Proteins 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000013076 target substance Substances 0.000 description 2
- JNYAEWCLZODPBN-JGWLITMVSA-N (2r,3r,4s)-2-[(1r)-1,2-dihydroxyethyl]oxolane-3,4-diol Chemical compound OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O JNYAEWCLZODPBN-JGWLITMVSA-N 0.000 description 1
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 1
- SCYULBFZEHDVBN-UHFFFAOYSA-N 1,1-Dichloroethane Chemical compound CC(Cl)Cl SCYULBFZEHDVBN-UHFFFAOYSA-N 0.000 description 1
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- HNAGHMKIPMKKBB-UHFFFAOYSA-N 1-benzylpyrrolidine-3-carboxamide Chemical compound C1C(C(=O)N)CCN1CC1=CC=CC=C1 HNAGHMKIPMKKBB-UHFFFAOYSA-N 0.000 description 1
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 description 1
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- FERIUCNNQQJTOY-UHFFFAOYSA-M Butyrate Chemical compound CCCC([O-])=O FERIUCNNQQJTOY-UHFFFAOYSA-M 0.000 description 1
- 229920002284 Cellulose triacetate Polymers 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- 102000004190 Enzymes Human genes 0.000 description 1
- 108090000790 Enzymes Proteins 0.000 description 1
- 241000588724 Escherichia coli Species 0.000 description 1
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 1
- JGFBQFKZKSSODQ-UHFFFAOYSA-N Isothiocyanatocyclopropane Chemical compound S=C=NC1CC1 JGFBQFKZKSSODQ-UHFFFAOYSA-N 0.000 description 1
- 239000005909 Kieselgur Substances 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 description 1
- VKEQBMCRQDSRET-UHFFFAOYSA-N Methylone Chemical compound CNC(C)C(=O)C1=CC=C2OCOC2=C1 VKEQBMCRQDSRET-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- NNLVGZFZQQXQNW-ADJNRHBOSA-N [(2r,3r,4s,5r,6s)-4,5-diacetyloxy-3-[(2s,3r,4s,5r,6r)-3,4,5-triacetyloxy-6-(acetyloxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6s)-4,5,6-triacetyloxy-2-(acetyloxymethyl)oxan-3-yl]oxyoxan-2-yl]methyl acetate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](OC(C)=O)[C@H]1OC(C)=O)O[C@H]1[C@@H]([C@@H](OC(C)=O)[C@H](OC(C)=O)[C@@H](COC(C)=O)O1)OC(C)=O)COC(=O)C)[C@@H]1[C@@H](COC(C)=O)O[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]1OC(C)=O NNLVGZFZQQXQNW-ADJNRHBOSA-N 0.000 description 1
- 235000011054 acetic acid Nutrition 0.000 description 1
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 1
- 125000002777 acetyl group Chemical group [H]C([H])([H])C(*)=O 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000008055 alkyl aryl sulfonates Chemical class 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 229940072049 amyl acetate Drugs 0.000 description 1
- PGMYKACGEOXYJE-UHFFFAOYSA-N anhydrous amyl acetate Natural products CCCCCOC(C)=O PGMYKACGEOXYJE-UHFFFAOYSA-N 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- RDHPKYGYEGBMSE-UHFFFAOYSA-N bromoethane Chemical compound CCBr RDHPKYGYEGBMSE-UHFFFAOYSA-N 0.000 description 1
- OBNCKNCVKJNDBV-UHFFFAOYSA-N butanoic acid ethyl ester Natural products CCCC(=O)OCC OBNCKNCVKJNDBV-UHFFFAOYSA-N 0.000 description 1
- PWLNAUNEAKQYLH-UHFFFAOYSA-N butyric acid octyl ester Natural products CCCCCCCCOC(=O)CCC PWLNAUNEAKQYLH-UHFFFAOYSA-N 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003093 cationic surfactant Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000502 dialysis Methods 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000000909 electrodialysis Methods 0.000 description 1
- 229940093499 ethyl acetate Drugs 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- WBJINCZRORDGAQ-UHFFFAOYSA-N formic acid ethyl ester Natural products CCOC=O WBJINCZRORDGAQ-UHFFFAOYSA-N 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- MNWFXJYAOYHMED-UHFFFAOYSA-M heptanoate Chemical compound CCCCCCC([O-])=O MNWFXJYAOYHMED-UHFFFAOYSA-M 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000003100 immobilizing effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 229910001629 magnesium chloride Inorganic materials 0.000 description 1
- 229940017219 methyl propionate Drugs 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- UUIQMZJEGPQKFD-UHFFFAOYSA-N n-butyric acid methyl ester Natural products CCCC(=O)OC UUIQMZJEGPQKFD-UHFFFAOYSA-N 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 125000005498 phthalate group Chemical class 0.000 description 1
- 239000002504 physiological saline solution Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 239000003495 polar organic solvent Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920005597 polymer membrane Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 235000019260 propionic acid Nutrition 0.000 description 1
- HNJBEVLQSNELDL-UHFFFAOYSA-N pyrrolidin-2-one Chemical compound O=C1CCCN1 HNJBEVLQSNELDL-UHFFFAOYSA-N 0.000 description 1
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- ILJSQTXMGCGYMG-UHFFFAOYSA-N triacetic acid Chemical compound CC(=O)CC(=O)CC(O)=O ILJSQTXMGCGYMG-UHFFFAOYSA-N 0.000 description 1
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 1
- 229910021642 ultra pure water Inorganic materials 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
- 239000000052 vinegar Substances 0.000 description 1
- 235000021419 vinegar Nutrition 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は精密ろ過膜の構造、特性
に関するものであり、特に大きい膜透過流束を維持する
ための濾過方式に使用される濾過膜に関するものである
。本発明の精密ろ過膜は、種々の高分子、微生物、酵母
、微粒子を含有あるいは懸濁する流体の分離、精製、回
収、濃縮などに適用され、特に濾過を必要とする微細な
微粒子を含有する流体からその微粒子を分離する必要の
あるあらゆる場合に適用することができ、例えば微粒子
を含有する各種の懸濁液、発酵液あるいは培養液などの
他、顔料の懸濁液などから微粒子を分離する場合にも適
用され、また微粒子を含む懸濁気体から微粒子を分離、
除去して気体を精製する、例えば医薬用アンプルへ充填
する無菌化窒素ガス、超純水製造装置への陽圧用ガスと
して充填する無塵、無菌のガスあるいはＩＣ製造ライン
における空調用無塵、無菌の空気などの製造のためにも
適用される。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure and characteristics of microfiltration membranes, and particularly to a filtration membrane used in a filtration system for maintaining a large membrane permeation flux. The microfiltration membrane of the present invention is applied to the separation, purification, recovery, concentration, etc. of fluids containing or suspending various polymers, microorganisms, yeast, and fine particles, and especially those containing fine particles that require filtration. It can be applied in any case where it is necessary to separate fine particles from a fluid, such as from various suspensions containing fine particles, fermentation liquids or culture liquids, as well as suspensions of pigments, etc. It is also applied in cases where fine particles are separated from suspended gases containing fine particles,
Remove and purify gases, such as sterilized nitrogen gas filled into pharmaceutical ampoules, dust-free and sterile gas filled as positive pressure gas into ultrapure water production equipment, or dust-free and sterile gas for air conditioning in IC manufacturing lines. It is also applied for the production of air etc.
【０００２】0002
【従来の技術】従来、膜を用いて懸濁物質を含有する原
流体から懸濁物質を分離する技術としては、例えば圧力
を駆動力とする逆浸透法、限外濾過法、精密濾過法、電
位差を駆動力とする電気透析法、濃度差を駆動力とする
拡散透析法等がある。これらの方法は、連続操作が可能
であり、分離操作中に温度やｐＨの条件を大きく変化さ
せることなく分離、精製あるいは濃縮ができ、粒子、分
子、イオン等の広範囲にわたって分離が可能であり、小
型プラント処理能力を大きく保つことができるので経済
的であり、分離操作に要するエネルギーが小さく、かつ
他の分離方法では難しい低濃度原流体の処理が可能であ
るなどの理由により広範囲に実施されている。そしてこ
れらの分離技術に用いられる膜としては、酢酸セルロー
ス、硝酸セルロース、再生セルロース、ポリスルホン、
ポリアクリロニトリル、ポリアミド、ポリイミド等の有
機高分子等を主体とした高分子膜や耐熱性、耐薬品性な
どの耐久性に優れている多孔質セラミック膜などがあり
、主としてコロイドの濾過を対象とする場合は限外濾過
膜が使用され、微細な粒子の濾過を対象とする精密濾過
ではそれに適した微孔を有する精密濾過膜が使用されて
いる。BACKGROUND ART Conventionally, techniques for separating suspended solids from a raw fluid containing suspended solids using a membrane include, for example, reverse osmosis, ultrafiltration, microfiltration, which uses pressure as a driving force, There are electrodialysis methods that use a potential difference as a driving force, and diffusion dialysis methods that use a concentration difference as a driving force. These methods can be operated continuously, can separate, purify, or concentrate without significantly changing temperature or pH conditions during the separation operation, and can separate a wide range of particles, molecules, ions, etc. It is economical because it can maintain a large processing capacity in a small plant, requires little energy for separation operations, and can process low-concentration raw fluids that are difficult to use with other separation methods, so it has been widely implemented. There is. The membranes used in these separation techniques include cellulose acetate, cellulose nitrate, regenerated cellulose, polysulfone,
There are polymer membranes mainly made of organic polymers such as polyacrylonitrile, polyamide, polyimide, etc., and porous ceramic membranes with excellent durability such as heat resistance and chemical resistance, and are mainly used for colloid filtration. For microfiltration, ultrafiltration membranes are used, and microfiltration membranes with suitable pores are used for precision filtration, which targets the filtration of fine particles.
【０００３】ところで近年、バイオテクノロジーの進歩
に伴い、高純度化、高性能化、高精密化が要求されるよ
うになり、精密濾過あるいは限外濾過技術の応用分野が
拡大しつつある。しかしながら、精密濾過あるいは限外
濾過においては膜を用いて微粒子を分離する場合に、濃
度分極の影響によりケーク層が生じて透過流体の流れに
抵抗が生じ、また膜の目詰まりによる抵抗が大きくなっ
て膜透過流束が急激にかつ著しく低下してしまうとう問
題があり、これが精密濾過あるいは限外濾過の実用化を
妨げる最大の原因であった。またそれに用いられる膜は
汚染されやすく、その防止対策が必要である。濾過方法
としては、濾過されるべき全ての流体が濾材（濾布や膜
など）とケーク層を通過して流体中に含まれている微粒
子を分離するいわゆるデッドエンド型濾過方式がある。
このデッドエンド型濾過方式では流体が通過して懸濁物
質が分離されるためには濾材とケーク層が含有する流体
の流れを妨げる抵抗に打ち勝つ圧力が必要であり、この
ため精密濾過あるいは限外濾過においては、このような
デッドエンド濾過を行うと膜透過流束が小さくなってし
まうのである。このため、クロスフロー型濾過方式をす
ることが考えられた。このクロスフロー型濾過方式は、
濾過膜の膜表面に平行に濾過すべき原流体を流し、流体
は濾過膜を通って反対側へ透過し、この原流体と透過流
体の流れが直交しているためにこのように称されている
。このクロスフロー型濾過方式は、膜に平行な原流体の
流れによって膜面上に形成されたケーク層がはぎ取られ
るので従来のデッドエンド型濾過方式に比べて膜透過流
束が大きく、大量の原流体を直接連続的に分離、精製、
濃縮が可能であり、濾過性向上のためのフロック生成剤
を必要とせず、そのため捕集された懸濁物質に助剤が混
入せず、膜の微孔径と目的物質との相互作用をコントロ
ールすることによりきわめて純粋な濾過流体が得られる
等の特徴を有する。[0003] In recent years, with the progress of biotechnology, higher purity, higher performance, and higher precision have been required, and the fields of application of microfiltration or ultrafiltration technology are expanding. However, when separating fine particles using a membrane in precision filtration or ultrafiltration, a cake layer is formed due to the influence of concentration polarization, creating resistance to the flow of the permeate fluid, and resistance increases due to membrane clogging. However, there is a problem in that the membrane permeation flux decreases rapidly and significantly, and this has been the biggest cause of hindering the practical application of precision filtration or ultrafiltration. Furthermore, the membrane used therein is easily contaminated, and measures to prevent this are required. As a filtration method, there is a so-called dead-end filtration method in which all the fluid to be filtered passes through a filter medium (filter cloth, membrane, etc.) and a cake layer to separate fine particles contained in the fluid. In this dead-end filtration system, in order for the fluid to pass through and the suspended solids to be separated, pressure must be applied to overcome the resistance of the filter medium and cake layer that impedes the flow of the fluid, and for this reason, microfiltration or ultrafiltration is required. In filtration, if such dead-end filtration is performed, the membrane permeation flux becomes small. For this reason, a cross-flow type filtration method was considered. This cross-flow filtration method
The raw fluid to be filtered is passed parallel to the membrane surface of the filtration membrane, and the fluid permeates through the filtration membrane to the opposite side. It is so called because the flow of the raw fluid and the permeated fluid are perpendicular to each other. There is. In this cross-flow filtration method, the cake layer formed on the membrane surface is stripped off by the flow of the raw fluid parallel to the membrane, so the membrane permeation flux is larger than in the conventional dead-end filtration method, and a large amount of Directly and continuously separates and purifies raw fluids.
It can be concentrated, does not require a flocculation agent to improve filtration, and therefore no auxiliary agent is mixed into the collected suspended solids, and the interaction between the membrane's micropore size and the target substance can be controlled. As a result, extremely pure filtration fluid can be obtained.
【０００４】0004
【発明が解決しようとする課題】上述のように、クロス
フロー型濾過方式は原理的には高度な分離技術であるが
、最大の問題である膜透過流束は、デッドエンド型濾過
方式に比べて大きいが、精密濾過方法としてこのクロス
フロー方式を採用しても十分高い膜透過流束が得られな
いという問題があった。また従来から行われている懸濁
物質と流体との分離の具体的な例を見ても、例えば発酵
液から菌体を分離する場合には、従来遠心分離法、ケー
ク濾過法、珪藻土濾過法などの一次濾過と精密濾過法等
の二次濾過が併用されているが、菌体等の分離ではプロ
セスの連続化が困難であり、酵素などの生成物が濾過助
剤に強く吸着することにより回収率が低下し、二次濾過
である精密濾過による菌体の収集の際には、膜面上に形
成されたケーク層や目詰まりによって濾過時間の経過と
共に膜透過流束が低下し、さらに遠心分離法により菌体
の活性が失われるという問題があった。[Problems to be Solved by the Invention] As mentioned above, the cross-flow filtration system is an advanced separation technology in principle, but the biggest problem is the membrane permeation flux compared to the dead-end filtration system. However, even if this cross-flow method is adopted as a precision filtration method, there is a problem in that a sufficiently high membrane permeation flux cannot be obtained. In addition, looking at specific examples of conventional separation of suspended solids and fluids, for example, when separating bacterial cells from fermentation liquid, conventional centrifugation, cake filtration, and diatomaceous earth filtration methods are used. Primary filtration, such as filtration, and secondary filtration, such as precision filtration, are used together, but it is difficult to make the process continuous when separating bacterial cells, etc., and products such as enzymes strongly adsorb to the filter aid. The recovery rate decreases, and when bacterial cells are collected by secondary filtration, the membrane permeation flux decreases as the filtration time passes due to the cake layer and clogging formed on the membrane surface. There was a problem in that the centrifugation method resulted in loss of bacterial activity.
【０００５】これらの問題を解決するために、従来から
濾過膜への原流体の流入を断続的に停止したり、濾過膜
の透過流体側の弁を閉止することにより、濾過膜の膜面
に垂直にかかる圧力を断続的になくすあるいは減少させ
たり、また濾過膜の透過液側から圧力を加え透過液側か
ら原流体側へ流体を流すことによって、濾過膜の原流体
側の膜面上に堆積しているケーク層や付着層を断続的に
取り除く「逆洗」と称する試みがなされている。しかし
、これら逆洗が行われた場合、ケーク層、付着層と膜と
の吸着力、結合力が小さい剛体粒子等の場合には「逆洗
」の後、透過流束が濾過開始初期の透過流束まで回復す
るが、酵母や微生物等の高吸着性、高圧縮性の懸濁物質
の場合「逆洗」を行っても、ケーク層や付着層が十分取
り除けないため、透過流束は回復せず徐々に低下して結
果として経済的な透過流束を得ることができなかった。[0005] In order to solve these problems, conventional methods have been used to intermittently stop the flow of the raw fluid into the filtration membrane, or to close the valve on the permeate side of the filtration membrane. By intermittently eliminating or reducing the vertical pressure, or by applying pressure from the permeate side of the filtration membrane and causing the fluid to flow from the permeate side to the raw fluid side, the membrane surface on the raw fluid side of the filtration membrane can be Attempts have been made to intermittently remove the deposited cake layer or adhesion layer, which is called "backwashing." However, when such backwashing is performed, in the case of rigid particles with small adsorption and bonding forces between the cake layer, adhesion layer and membrane, after backwashing, the permeation flux decreases to the permeation flux at the initial stage of filtration. However, in the case of highly adsorbent and highly compressible suspended substances such as yeast and microorganisms, even if backwashing is performed, the cake layer and adhesion layer cannot be sufficiently removed, so the permeation flux will recover. As a result, it was not possible to obtain an economical permeation flux.
【０００６】[0006]
【問題を解決するための手段】本発明は、上述した従来
技術にあった問題点を解決するために試されたものであ
って、実用性のある高い膜透過流束を持つ新規な精密ろ
過膜を提供することを目的とするものである。すなわち
本発明は、懸濁物を含む懸濁液からと懸濁物質と液体と
を分離する目的において、濾過膜の表面が親水性の高い
セルローズ層で覆われて且つ高い純水透過流束特性と表
面開孔率を有することを特徴とする酢酸セルローズ精密
ろ過膜を提供する。以下、本発明の精密ろ過膜およびそ
の製法について以下に詳しく説明する。[Means for Solving the Problems] The present invention has been tried to solve the problems in the prior art described above, and provides a novel precision filtration system with a practical and high membrane permeation flux. The purpose is to provide a membrane. That is, the present invention provides a filter membrane whose surface is covered with a highly hydrophilic cellulose layer and which has high pure water permeation flux characteristics for the purpose of separating suspended substances and liquid from a suspension containing suspended substances. Provided is a cellulose acetate microfiltration membrane characterized by having a surface porosity of Hereinafter, the microfiltration membrane of the present invention and its manufacturing method will be explained in detail below.
【０００７】酢酸セルローズから精密ろ過膜を製造する
時は、通常酢酸セルローズを溶液中から相分離させる方
法が使用されるが、本発明においてもかかる方法が好ま
しく使用される。即ち、酢酸セルローズの良溶剤、貧溶
剤及び又は非溶剤を含む酢酸セルローズ溶液をつくり、
この溶液を支持体に塗布又は流延した後に、これを乾燥
して酢酸セルローズの皮膜を形成し、あるいは最後に皮
膜を支持体から剥離すれば精密ろ過膜が得られる。ここ
で良溶剤とは、酢酸セルローズを溶解し、貧溶剤及び非
溶剤よりも揮発性が高いか又は低沸点の溶剤を指す。[0007] When producing a microfiltration membrane from cellulose acetate, a method is usually used in which cellulose acetate is phase-separated from a solution, and such a method is preferably used in the present invention. That is, a cellulose acetate solution containing a good solvent, a poor solvent and/or a non-solvent for cellulose acetate is prepared,
After applying or casting this solution onto a support, it is dried to form a film of cellulose acetate, or a microfiltration membrane can be obtained by finally peeling the film from the support. The term "good solvent" as used herein refers to a solvent that dissolves cellulose acetate and has higher volatility or lower boiling point than poor solvents and non-solvents.
【０００８】酢酸セルローズの一般的な良溶剤としては
、塩化メチレン、クロロホルム、塩化エチレン、塩化エ
チリデン、トリクロルエタン、テトラクロルエタン、臭
化エチルの如きハロゲン化炭化水素類、アセトン、メチ
ルエチルケトン、メチルイソブチルケトン、シクロヘキ
サノンの如きケトン類、ジオキサン、テトラヒドロフラ
ン、メチルセロソルブ、エチルセロソルブの如きエーテ
ル類、ギ酸メチル、ギ酸エチル、ギ酸プロピル、酢酸メ
チル、酢酸エチル、酢酸アミル、プロピオン酸メチル、
酪酸エチル、酪酸メチルの如きエステル類、ギ酸、酢酸
、プロピオン酸の如き脂肪酸、ジメチルホルムアミド、
ジメチルスルホキシド、Ｎ−メチル−２−ピロリドン、
２−ピロリドン、ホルムアミドの如き極性有機溶剤など
の中から１種以上のが選ばれる。良溶剤は沸点が８０℃
以下のものが取扱上特に好ましく用いられる。General good solvents for cellulose acetate include halogenated hydrocarbons such as methylene chloride, chloroform, ethylene chloride, ethylidene chloride, trichloroethane, tetrachloroethane, and ethyl bromide, acetone, methyl ethyl ketone, and methyl isobutyl ketone. , ketones such as cyclohexanone, ethers such as dioxane, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, amyl acetate, methyl propionate,
Esters such as ethyl butyrate and methyl butyrate, fatty acids such as formic acid, acetic acid, and propionic acid, dimethylformamide,
dimethyl sulfoxide, N-methyl-2-pyrrolidone,
One or more types are selected from polar organic solvents such as 2-pyrrolidone and formamide. A good solvent has a boiling point of 80℃
The following are particularly preferably used for handling purposes.
【０００９】ここで貧溶剤とは、酢酸セルローズを実質
的に溶解しないが膨潤させる溶剤であって、良溶剤と混
和するものが好ましい。貧溶剤の具体例としては、メタ
ノール、エタノール、ｎ−プロパノール、ｉ−プロパノ
ール、ブタノールの如きアルコール類が特に好ましく用
いられる。特に良溶剤よりも揮発性が低いかあるいは沸
点の高い溶剤が好ましい。[0009] Here, the poor solvent is a solvent that does not substantially dissolve cellulose acetate but swells it, and is preferably a solvent that is miscible with a good solvent. As specific examples of the poor solvent, alcohols such as methanol, ethanol, n-propanol, i-propanol, and butanol are particularly preferably used. In particular, a solvent with lower volatility or higher boiling point than a good solvent is preferred.
【００１０】更に非溶剤とは、酢酸セルローズを実質的
に溶解膨潤させず、貧溶剤と混和する溶剤である。非溶
剤は多くの場合は水であり、時にはヘキサン、ヘプタン
、デカンの如き脂肪族炭化水素類、シクロヘキサンの如
き脂環式炭化水素類、トルエン、ベンゼン、テトラリン
の如き芳香族炭化水素類、エチレングリコール、ジエチ
レングリコール、トリエチレングリコール、グリセリン
の如き多価アルコールなどが使用される。上記の三種の
溶剤はそれぞれ二種以上を混合して使用できることはい
うまでもない。Furthermore, the non-solvent is a solvent that does not substantially dissolve or swell cellulose acetate and is miscible with a poor solvent. The non-solvent is often water, and sometimes aliphatic hydrocarbons such as hexane, heptane, decane, cycloaliphatic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene, benzene, tetralin, ethylene glycol. , polyhydric alcohols such as diethylene glycol, triethylene glycol, and glycerin. It goes without saying that two or more of the above three solvents can be used in combination.
【００１１】酢酸セルローズの溶液には上記溶剤の他に
、有機リン酸エステルやフタル酸エステルの如き可塑剤
や、高級カルボン酸塩、高級アルコール硫酸エステル塩
、アルキルアリルスルホン酸塩の如きアニオン系界面活
性剤、アミン塩、アンモニウム塩の如きカチオン界面活
性剤、アルキルアリルエーテル、アルキルフェニルエー
テル、ポリオキシアルキルフェニルエーテル、ソルビタ
ンモノアルキルエステル、ポリエチレンオキサイドの如
きノニオン系界面活性剤、塩化ナトリウム、塩化マグネ
シウム、硫酸ナトリウムの如き無機塩類も添加すること
ができる。In addition to the above-mentioned solvents, the cellulose acetate solution contains plasticizers such as organic phosphates and phthalates, and anionic interfaces such as higher carboxylates, higher alcohol sulfates, and alkylaryl sulfonates. Activators, cationic surfactants such as amine salts and ammonium salts, nonionic surfactants such as alkyl allyl ethers, alkylphenyl ethers, polyoxyalkylphenyl ethers, sorbitan monoalkyl esters, polyethylene oxide, sodium chloride, magnesium chloride, Inorganic salts such as sodium sulfate can also be added.
【００１２】使用する酢酸セルローズは酢化度が４２％
から６２％のジアセテートや、トリアセテートと呼ばれ
るものを用いる。酢化度が５０％から６０％の範囲にあ
るものが微孔形成上好ましい。特に５５％から５９％の
ものが好ましい。酢化度の異なる二種以上の酢酸セルロ
ーズを混合して用いることもできる。この場合も、混合
した酢酸セルローズの平均酢化度が５０％から６０％の
範囲にあることが好ましい。ここで酢化度とは、酢酸セ
ルローズをアルカリで完全に鹸化して生成した酢酸重量
の、元の酢酸セルローズ重量に対する割合を、百分率で
表したものである。従ってセルローズのすべての水酸基
がアセチル基になっている三酢酸セルローズにおいては
、その酢化度は６２．５％となる。[0012] The cellulose acetate used has an acetylation degree of 42%.
to 62% diacetate or triacetate. It is preferable that the degree of acetylation is in the range of 50% to 60% from the viewpoint of forming micropores. Particularly preferred is 55% to 59%. It is also possible to use a mixture of two or more types of cellulose acetate having different degrees of acetylation. In this case as well, the average degree of acetylation of the mixed cellulose acetate is preferably in the range of 50% to 60%. Here, the degree of acetylation is the ratio of the weight of acetic acid produced by completely saponifying cellulose acetate with an alkali to the weight of the original cellulose acetate, expressed as a percentage. Therefore, in cellulose triacetate, in which all the hydroxyl groups in cellulose are acetyl groups, the degree of acetylation is 62.5%.
【００１３】このようにして調製された酢酸セルローズ
溶液は硝子板、ステンレスベルト、プラスチックフィル
ムあるいは織布や不織布といった支持体上に流延あるい
は塗布される。その後支持体上の皮膜は乾燥される。乾
燥は皮膜中で酢酸セルローズを相分離させるためにおこ
なわれ、通常は良溶剤の沸点以下、好ましくは３５℃以
下の温度で乾燥される。この場合乾燥時間を長くすれば
、即ち徐々に乾燥すれば、精密ろ過膜の孔径は大きくな
り、膜の表面と裏面との孔径差は小さくなる傾向がある
。逆に乾燥を速くするように乾燥風量を多くしたり、乾
燥温度を高くしたりすると、孔径は小さくなり、膜の表
裏の孔径差は大きくなる傾向がある。また酢酸セルロー
ズ溶液に用いる良溶剤として揮発性の低い溶剤を用いた
り、沸点の高い溶剤を用いると、孔径は大きくなり表裏
の孔径差は小さくなる傾向がある。通常膜が空気と接し
ている側の孔径は支持体に接している側の孔径よりも小
さくなるが、支持体と直接接触している厚さ数ミクロン
部分の孔径だけはそのすぐ内部の孔径よりもかえって小
さくなる傾向がある。The cellulose acetate solution thus prepared is cast or coated onto a support such as a glass plate, a stainless steel belt, a plastic film, or a woven or nonwoven fabric. The coating on the support is then dried. Drying is carried out to cause phase separation of cellulose acetate in the film, and is usually carried out at a temperature below the boiling point of a good solvent, preferably below 35°C. In this case, if the drying time is increased, that is, if the membrane is gradually dried, the pore size of the microfiltration membrane becomes larger, and the difference in pore size between the front and back surfaces of the membrane tends to become smaller. On the other hand, if the drying air volume is increased or the drying temperature is increased to speed up drying, the pore size tends to become smaller and the difference in pore size between the front and back sides of the membrane becomes larger. Furthermore, if a solvent with low volatility or a solvent with a high boiling point is used as a good solvent for the cellulose acetate solution, the pore size tends to increase and the difference in pore size between the front and back surfaces tends to become smaller. Normally, the pore diameter on the side of the membrane that is in contact with air is smaller than the pore diameter on the side that is in contact with the support, but the pore diameter of the part several microns thick that is in direct contact with the support is smaller than the pore diameter immediately inside. On the contrary, it tends to become smaller.
【００１４】支持体に接触している内部よりも孔径の小
さな部分を特公昭５５−６４０６号に記載されているよ
うな方法、例えば接着剤有するプラスチックフィルム上
に膜を形成した後に表層のせいぜい５μｍ以下を剥離す
れば、表裏で孔径差が２倍から１００倍も異なる精密ろ
過膜が得られる。このように膜の表裏で孔径差の大きな
膜は、孔径の小さな部分で微粒子を捕捉する一方、その
反対側では孔径が大きいのでろ過抵抗が小さいという特
徴がある。特公昭５５−６４０６号の方法により膜の表
層を除去した時にはさらに膜の表面開孔率を飛躍的に向
上させることができる。通常製膜直後の表面開孔率は製
膜溶液組成、特に酢酸セルローズ濃度や乾燥条件により
異なるが、３０％を越えることはほとんどない。酢酸セ
ルローズ濃度が高い時や乾燥温度を高くしたり風量を多
くしたりして急乾燥したりして時は、表面開孔率が１０
％以下になることも稀ではない。しかし表層の数μｍを
除去することにより、開孔率は容易に３０％以上に大き
くすることができる。表層を除去した内部の開孔率は膜
全体の空隙率（膜中の空隙体積／見掛け上の膜体積×１
００）にほぼ比例する。通常膜の空隙率は５０％から８
５％であるので、表層を除去することにより表面開孔率
５０％から８５％の膜が容易に得られる。[0014] The part of the surface which is in contact with the support and which has a smaller pore diameter than the inner part is prepared by the method described in Japanese Patent Publication No. 55-6406, for example, after forming a film on a plastic film with an adhesive, the surface layer has a diameter of at most 5 μm. By peeling off the following, a microfiltration membrane with a difference in pore size between 2 and 100 times between the front and back can be obtained. A membrane with such a large difference in pore size between the front and back sides of the membrane has the characteristic that while the part with the smaller pore size traps fine particles, the pore size on the opposite side is larger, resulting in lower filtration resistance. When the surface layer of the membrane is removed by the method disclosed in Japanese Patent Publication No. 55-6406, the surface porosity of the membrane can be further improved dramatically. Usually, the surface porosity immediately after film formation varies depending on the composition of the film forming solution, especially the cellulose acetate concentration and drying conditions, but it rarely exceeds 30%. When the concentration of cellulose acetate is high, or when drying is performed rapidly by increasing the drying temperature or air volume, the surface porosity becomes 10.
It is not uncommon for it to be less than %. However, by removing several μm of the surface layer, the porosity can be easily increased to 30% or more. The internal porosity after removing the surface layer is the porosity of the entire membrane (void volume in the membrane/apparent membrane volume x 1
00). Normal membrane porosity is 50% to 8
5%, a membrane with a surface porosity of 50% to 85% can be easily obtained by removing the surface layer.
【００１５】このようにして製膜した酢酸セルローズ膜
の表面に蛋白質や菌体が付着しにくくするためには、こ
の膜をアルカリ溶液中で表面のみ鹸化して、膜表面を再
生セルローズに変えてやればよい。ここで用いるアルカ
リはＮａＯＨ、ＫＯＨの如き一般的なアルカリならば何
でもよい。アルカリの濃度は室温で処理する時は０．１
規定から１規定の範囲が好ましく、特に０．２規定から
０．６規定の範囲が好ましい。この好ましい濃度は処理
する温度が高くなると低めに、処理温度が低くなると高
めにする必要があるのは言うまでもない。鹸化処理時間
を調節して、膜の平均酢化度が処理前よりも１％から１
０％減少するようにすると、膜の物理的力学的特性はあ
まり変化させないで表面の化学特性のみを大きく変化さ
せることができて好ましい。In order to make it difficult for proteins and microbial cells to adhere to the surface of the cellulose acetate membrane thus formed, only the surface of this membrane is saponified in an alkaline solution to change the membrane surface to regenerated cellulose. Just do it. The alkali used here may be any common alkali such as NaOH or KOH. The concentration of alkali is 0.1 when processing at room temperature.
A range of 1N to 1N is preferred, and a range of 0.2N to 0.6N is particularly preferred. Needless to say, this preferable concentration needs to be lowered as the processing temperature becomes higher, and higher as the processing temperature becomes lower. By adjusting the saponification treatment time, the average degree of acetylation of the membrane is 1% to 1% higher than before treatment.
A reduction of 0% is preferable because only the chemical properties of the surface can be significantly changed without significantly changing the physical and mechanical properties of the film.
【００１６】透過流束を高めるためには濾過膜の膜面に
垂直にかかる圧力を断続的になくすあるいは減少させる
「逆洗」を行った際、ケーク層や付着層は膜表面からは
ぎ取られる必要があるが、ケーク層、付着層と膜との結
合力が大きい場合には部分的あるいはほとんどケーク層
、付着層を取り除くことはできず、これら結合力を減少
させる必要があった。また、流体を透過液側から原流体
側に透過させる「逆洗」の際、濾過膜の透過抵抗が大き
い場合はケーク層、付着層をはぎ取る方向にかかる力が
低下し、上記同様にケーク層、付着層を取り除くことは
できなかった。本発明では、ケーク層、付着層と膜面と
の結合力を減少させる方法として濾過膜の表面の親水性
にし、特に表面を再生セルローズにすることにより蛋白
質との結合力を小さくできた。一方膜透過抵抗を低下さ
せることにより逆洗時に逆洗液を抵抗少なく、従ってケ
ーク層を剥ぎ取る力を損なわないで逆洗できるため、逆
洗による透過流束の回復が大きくなった。本発明は、「
逆洗」操作を行う場合に限定されず、クロスフロー型濾
過方式で原流体の流束を極端に高めたり、回転円筒型濾
過器のようにケース層や付着層を剥ぎ取る剪断力が極端
に大きいときは逆洗操作を行わなくても効果が顕著であ
る。In order to increase the permeation flux, the cake layer and adhesion layer are stripped off from the membrane surface when ``backwashing'' is performed, which intermittently eliminates or reduces the pressure applied perpendicularly to the membrane surface of the filtration membrane. However, if the bonding force between the cake layer, adhesion layer and the film is large, it is not possible to partially or almost remove the cake layer or adhesion layer, and it is necessary to reduce these bonding forces. In addition, during "backwashing" in which fluid permeates from the permeate side to the source fluid side, if the permeation resistance of the filtration membrane is large, the force applied in the direction of peeling off the cake layer and adhesion layer decreases, and as above, the cake layer , it was not possible to remove the adhesion layer. In the present invention, as a method of reducing the bonding force between the cake layer, the adhesion layer, and the membrane surface, the bonding force with proteins can be reduced by making the surface of the filtration membrane hydrophilic, and in particular by making the surface of regenerated cellulose. On the other hand, by lowering the membrane permeation resistance, the resistance of the backwash liquid during backwashing was reduced, and therefore backwashing was possible without impairing the ability to peel off the cake layer, resulting in greater recovery of permeation flux by backwashing. The present invention is “
This is not limited to cases where a cross-flow filtration method is used to extremely increase the flux of the raw fluid, or when the shearing force that strips off the case layer or adhesion layer is extremely high, such as with a rotating cylindrical filter. When the size is large, the effect is significant even without backwashing.
【００１７】本発明の精密ろ過膜を用いるクロスフロー
濾過方法を図１に示す。図２はクロスフロー濾過器の断
面図を表しており、懸濁物質が膜面上でケーク層を形成
している状態を示している。A cross-flow filtration method using the microfiltration membrane of the present invention is shown in FIG. FIG. 2 shows a cross-sectional view of a cross-flow filter, showing a state in which suspended solids form a cake layer on the membrane surface.
【００１８】[0018]
【実施例】以下に具体例をあげて本発明を更に詳しく説
明するが、本発明はこれに限定されるものではない。
実施例１
次の組成の酢酸セルローズ溶液を調製する。
酢酸セルローズ（酢過度５５．０） ７．０部グ
リセリン
０．２部塩化メチレン
５４．０部メタノール
３５．５
部水
４．３部この溶液を、ニトロセ
ルローズが塗布され乾燥されたポリエステルシート上に
流延し、２５℃で２０分、続いて８０℃で３０分乾燥し
、ポリエステルシートから酢酸セルローズの膜を、その
支持体側に接している表層のみを除き、剥離する。これ
を０．３規定のＮａＯＨ溶液中で２３℃５分間鹸化した
後、水洗乾燥した。できた膜の平均孔径は（ＡＳＴＭ−
Ｆ３１６の方法による）０．２５ミクロン、２５℃水の
初期流束は２００ｍｌ／ｋｇ分、平均酢化度は５１であ
った。また走査型電子顕微鏡による表面および裏面の観
察による孔径の相違は、約２０倍であった。膜の空隙率
は６９％であった。EXAMPLES The present invention will be explained in more detail with reference to specific examples, but the present invention is not limited thereto. Example 1 A cellulose acetate solution having the following composition is prepared. Cellulose acetate (vinegar excess 55.0) 7.0 parts glycerin
0.2 part methylene chloride
54.0 parts methanol
35.5
Department water
4.3 parts of this solution was cast onto a polyester sheet coated with nitrocellulose and dried, and dried at 25°C for 20 minutes and then at 80°C for 30 minutes to remove the cellulose acetate film from the polyester sheet. Remove only the surface layer that is in contact with the support and peel it off. This was saponified in a 0.3N NaOH solution at 23°C for 5 minutes, then washed with water and dried. The average pore size of the resulting membrane is (ASTM-
F316 method) 0.25 micron, the initial flux of 25° C. water was 200 ml/kg, and the average degree of acetylation was 51. Furthermore, the difference in pore diameters observed by scanning electron microscopy on the front and back surfaces was approximately 20 times larger. The porosity of the membrane was 69%.
【００１９】比較例１
実施例１の方法で製膜した膜の、その支持体側に接して
いる表層を剥離除去せず、さらに鹸化も行わずにそのま
まろ過試験に用いる。この膜の支持体に接していた側の
表面開孔率は約２０％であった。Comparative Example 1 The surface layer of the membrane formed by the method of Example 1 in contact with the support was not peeled off or saponified, and used as it was for a filtration test. The surface porosity of this membrane on the side that was in contact with the support was about 20%.
【００２０】実施例２
比較例１の膜を０．３規定のＮａＯＨ溶液中で２３℃５
分間鹸化した後、水洗乾燥した。Example 2 The membrane of Comparative Example 1 was heated at 23° C. in a 0.3N NaOH solution.
After saponifying for a minute, it was washed with water and dried.
【００２１】実施例３
大腸菌（ＩＦＯ−３３０１）を０．９ｗｔ／％の生理食
塩水に１ｄｒｙ ｇ／ｌ の含有率で分離させたものを
懸濁液として用い、実施例１および２および比較例１で
つくった精密濾過膜を用いてクロスフロー濾過を行った
。使用したモジュールは有効膜面積１００ｃｍ２ の薄
層流路式のもので、実験条件は圧力差０．５ｋｇ／ｃｍ
２ 、原流体の流量１０１／ｍｉｎ 、液温度２５℃で
あった。濾過開始後原流体を送るポンプを断続的に停止
して逆洗を行った。逆洗はポンプ運転１５０秒、停止３
０秒で操作した。図３に透過流束の経時変化を示した。
この結果、表面を鹸化処理して再生セルローズとした膜
は鹸化処理をしない膜よりも長時間十日流束を高く維持
できた。また表面開孔率の高い膜は低い膜よりも長時間
十日流束を高く維持できた。Example 3 Escherichia coli (IFO-3301) was separated in 0.9 wt/% physiological saline at a content of 1 dry g/l and used as a suspension to prepare Examples 1 and 2 and Comparative Examples. Cross-flow filtration was performed using the precision filtration membrane prepared in 1. The module used was a thin layer flow channel type with an effective membrane area of 100 cm2, and the experimental conditions were a pressure difference of 0.5 kg/cm.
2, the flow rate of the raw fluid was 101/min, and the liquid temperature was 25°C. After the filtration was started, the pump that sent the raw fluid was stopped intermittently to perform backwashing. For backwashing, run the pump for 150 seconds, then stop 3.
It was operated in 0 seconds. Figure 3 shows the change in permeation flux over time. As a result, the membrane whose surface was made of regenerated cellulose by saponification treatment was able to maintain a higher flux for a longer period of 10 days than the membrane without saponification treatment. Furthermore, membranes with high surface porosity were able to maintain a higher flux for a longer period of time than membranes with low surface porosity.
【００２２】[0022]
【発明の効果】本発明によれば、基本的には逆洗を伴う
濾過方式において高い膜透過流束が得られ、それによっ
て種々の懸濁物質を含有する液体から各懸濁成分の分離
、回収、精製、濃縮などがきわめて効率的しかも経済的
に行われる。そしてさらにプロセスの連続化及び装置の
小型化が可能であり、膜の選択性を利用して目的物のみ
を連続的に選択的に分離刷ることができ、酵母や菌体な
どを反応液中に固定することよりバイオリアクターへの
応用ができ、従来技術に比べて運転管理が容易でかつ高
濃度で運転が可能であり、膜の透過性を回復させるため
に特別な洗浄などを必要としないなど諸々の効果が奏せ
られる。Effects of the Invention According to the present invention, a high membrane permeation flux can be obtained basically in a filtration method that involves backwashing, thereby separating each suspended component from a liquid containing various suspended substances. Recovery, purification, concentration, etc. are performed extremely efficiently and economically. Furthermore, it is possible to make the process continuous and downsize the equipment, and by utilizing the selectivity of the membrane, it is possible to continuously and selectively separate and print only the target substance, making it possible to remove yeast and bacterial cells from the reaction solution. By immobilizing it, it can be applied to bioreactors, and compared to conventional technology, it is easier to manage and operate at higher concentrations, and does not require special cleaning to restore membrane permeability. Various effects can be produced.
【００２３】[0023]
【図１】本濾過膜を用いるクロスフロー濾過方法の概念
を示した説明図である。図において、供給タンク１内の
懸濁液を配管２を経てポンプ３により濾過膜を内蔵した
モジュール５通して循環する。この際懸濁液の圧力は圧
力調整バルブ８によって調整する。この圧力を圧力計４
により、液の流量はフローメーター９により読み取る。
逆洗はポンプ３を停止することにより行われる。FIG. 1 is an explanatory diagram showing the concept of a cross-flow filtration method using the present filtration membrane. In the figure, a suspension in a supply tank 1 is circulated via a pipe 2 by a pump 3 through a module 5 containing a filtration membrane. At this time, the pressure of the suspension is adjusted by a pressure regulating valve 8. This pressure is measured by pressure gauge 4
Accordingly, the flow rate of the liquid is read by the flow meter 9. Backwashing is performed by stopping the pump 3.
【００２４】[0024]
【図２】クロスフロー濾過器内の断面図であり、懸濁物
質が濾過膜の表面上にケーク層を形成している状態を表
している。FIG. 2 is a cross-sectional view of the inside of the cross-flow filter, showing a state in which suspended solids form a cake layer on the surface of the filtration membrane.
【００２５】[0025]
【図３】周期的に逆洗を行った場合の透過流束の経時変
化を示している。FIG. 3 shows the change in permeation flux over time when backwashing is performed periodically.
【００２６】[0026]
１ 供給タンク
２ 一次側配管３ ポンプ
４、７ 圧力計５
ろ過モジュール
６ 透過液側配管
８ 圧力調製バルブ
９ フローメーター
１０ 透過液タンク1 Supply tank
2 Primary side piping 3 Pump
4, 7 Pressure gauge 5
filtration module
6 Permeate side piping 8 Pressure adjustment valve
9 Flow meter 10 Permeate tank
Claims (3)
ルローズ微孔性膜をアルカリ鹸化し、平均酢化度を元の
酢化度より３％から１０％低下させたことを特徴とする
、クロスフローろ過用精密ろ過膜。[Claim 1] Cellulose acetate microporous membrane having an average degree of acetylation of 50% to 60% is saponified with alkali to reduce the average degree of acetylation by 3% to 10% from the original degree of acetylation. , precision filtration membrane for cross-flow filtration.
１の精密ろ過膜。2. The microfiltration membrane according to claim 1, which has a surface porosity of 30% or more.
なる異方性孔構造を有し、その孔径が大なる表面の孔径
が反対側表面の孔径の２倍から１００倍の範囲であるこ
とを特徴とする、請求項２の精密ろ過膜。3. The membrane has an anisotropic pore structure in which the pore diameter decreases continuously in the thickness direction, and the pore diameter on the surface with the larger pore diameter is in the range of 2 to 100 times the pore diameter on the opposite surface. The microfiltration membrane according to claim 2, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1037791A JPH04250834A (en) | 1991-01-07 | 1991-01-07 | Precision filter membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1037791A JPH04250834A (en) | 1991-01-07 | 1991-01-07 | Precision filter membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04250834A true JPH04250834A (en) | 1992-09-07 |
Family
ID=11748445
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1037791A Pending JPH04250834A (en) | 1991-01-07 | 1991-01-07 | Precision filter membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04250834A (en) |
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| JP2010214228A (en) * | 2009-03-13 | 2010-09-30 | Panasonic Electric Works Co Ltd | Method for manufacturing filtration membrane for water treatment apparatuses, filtration membrane for water treatment apparatuses, and water treatment apparatus equipped with filtration membrane for water treatment apparatuses |
| CN104128044A (en) * | 2014-08-09 | 2014-11-05 | 李宗泽 | Filter material, filter element, filter module and machining method thereof |
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| WO2003015902A2 (en) * | 2001-08-14 | 2003-02-27 | Pall Corporation | High strength asymmetric cellulosic membrane |
| WO2003015902A3 (en) * | 2001-08-14 | 2003-11-13 | Pall Corp | High strength asymmetric cellulosic membrane |
| FR2862658A1 (en) * | 2003-11-21 | 2005-05-27 | Sartorius Gmbh | Producing fruit brandy, comprises using ultra-filtration, for a diluted fruit brandy feed, giving a filtrate as a clarified and stable fruit brandy |
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