JPH0317531B2 - - Google Patents
Info
- Publication number
- JPH0317531B2 JPH0317531B2 JP62000319A JP31987A JPH0317531B2 JP H0317531 B2 JPH0317531 B2 JP H0317531B2 JP 62000319 A JP62000319 A JP 62000319A JP 31987 A JP31987 A JP 31987A JP H0317531 B2 JPH0317531 B2 JP H0317531B2
- Authority
- JP
- Japan
- Prior art keywords
- porous membrane
- polyolefin
- membrane
- polymer
- water
- 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.)
- Expired - Lifetime
Links
- 239000012528 membrane Substances 0.000 claims description 176
- 239000000178 monomer Substances 0.000 claims description 84
- 239000011148 porous material Substances 0.000 claims description 84
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 72
- 229920000642 polymer Polymers 0.000 claims description 59
- 229920000098 polyolefin Polymers 0.000 claims description 58
- 238000000034 method Methods 0.000 claims description 50
- 230000000717 retained effect Effects 0.000 claims description 30
- 239000002904 solvent Substances 0.000 claims description 29
- OMNKZBIFPJNNIO-UHFFFAOYSA-N n-(2-methyl-4-oxopentan-2-yl)prop-2-enamide Chemical compound CC(=O)CC(C)(C)NC(=O)C=C OMNKZBIFPJNNIO-UHFFFAOYSA-N 0.000 claims description 25
- 238000004132 cross linking Methods 0.000 claims description 24
- 229920006037 cross link polymer Polymers 0.000 claims description 19
- 239000012510 hollow fiber Substances 0.000 claims description 17
- -1 ethylene, propylene, 4 -Methyl-1-pentene Chemical class 0.000 claims description 11
- 239000003960 organic solvent Substances 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 238000001704 evaporation Methods 0.000 claims description 2
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 claims 2
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 claims 2
- 230000000379 polymerizing effect Effects 0.000 claims 1
- 238000006116 polymerization reaction Methods 0.000 description 29
- 239000000243 solution Substances 0.000 description 26
- 230000035699 permeability Effects 0.000 description 23
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 21
- 239000003505 polymerization initiator Substances 0.000 description 14
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 11
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 9
- CCJAYIGMMRQRAO-UHFFFAOYSA-N 2-[4-[(2-hydroxyphenyl)methylideneamino]butyliminomethyl]phenol Chemical compound OC1=CC=CC=C1C=NCCCCN=CC1=CC=CC=C1O CCJAYIGMMRQRAO-UHFFFAOYSA-N 0.000 description 8
- 230000001186 cumulative effect Effects 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 7
- 239000004342 Benzoyl peroxide Substances 0.000 description 7
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 7
- 235000019400 benzoyl peroxide Nutrition 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000000758 substrate Substances 0.000 description 7
- 238000010828 elution Methods 0.000 description 6
- 230000005855 radiation Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- KOMNUTZXSVSERR-UHFFFAOYSA-N 1,3,5-tris(prop-2-enyl)-1,3,5-triazinane-2,4,6-trione Chemical compound C=CCN1C(=O)N(CC=C)C(=O)N(CC=C)C1=O KOMNUTZXSVSERR-UHFFFAOYSA-N 0.000 description 5
- 229920001577 copolymer Polymers 0.000 description 5
- 230000014759 maintenance of location Effects 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 238000012719 thermal polymerization Methods 0.000 description 5
- MYRTYDVEIRVNKP-UHFFFAOYSA-N 1,2-Divinylbenzene Chemical compound C=CC1=CC=CC=C1C=C MYRTYDVEIRVNKP-UHFFFAOYSA-N 0.000 description 4
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 4
- 239000004698 Polyethylene Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- ZIUHHBKFKCYYJD-UHFFFAOYSA-N n,n'-methylenebisacrylamide Chemical compound C=CC(=O)NCNC(=O)C=C ZIUHHBKFKCYYJD-UHFFFAOYSA-N 0.000 description 4
- 150000002978 peroxides Chemical class 0.000 description 4
- 229920000573 polyethylene Polymers 0.000 description 4
- 238000009736 wetting Methods 0.000 description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- 239000008280 blood Substances 0.000 description 3
- 210000004369 blood Anatomy 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000007598 dipping method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229920001477 hydrophilic polymer Polymers 0.000 description 3
- 230000002209 hydrophobic effect Effects 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 3
- 150000002576 ketones Chemical class 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 3
- 229910052753 mercury Inorganic materials 0.000 description 3
- 210000001724 microfibril Anatomy 0.000 description 3
- 239000012046 mixed solvent Substances 0.000 description 3
- 239000012466 permeate Substances 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- RYPKRALMXUUNKS-UHFFFAOYSA-N 2-Hexene Natural products CCCC=CC RYPKRALMXUUNKS-UHFFFAOYSA-N 0.000 description 2
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- ZQMIGQNCOMNODD-UHFFFAOYSA-N diacetyl peroxide Chemical compound CC(=O)OOC(C)=O ZQMIGQNCOMNODD-UHFFFAOYSA-N 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 238000002715 modification method Methods 0.000 description 2
- DNTMQTKDNSEIFO-UHFFFAOYSA-N n-(hydroxymethyl)-2-methylprop-2-enamide Chemical compound CC(=C)C(=O)NCO DNTMQTKDNSEIFO-UHFFFAOYSA-N 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229920001223 polyethylene glycol Polymers 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 230000008961 swelling Effects 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- ASFDEZUYEYZNGZ-UHFFFAOYSA-N (3-bromobenzoyl) 3-bromobenzenecarboperoxoate Chemical compound BrC1=CC=CC(C(=O)OOC(=O)C=2C=C(Br)C=CC=2)=C1 ASFDEZUYEYZNGZ-UHFFFAOYSA-N 0.000 description 1
- KEOLYBMGRQYQTN-UHFFFAOYSA-N (4-bromophenyl)-phenylmethanone Chemical compound C1=CC(Br)=CC=C1C(=O)C1=CC=CC=C1 KEOLYBMGRQYQTN-UHFFFAOYSA-N 0.000 description 1
- NOBYOEQUFMGXBP-UHFFFAOYSA-N (4-tert-butylcyclohexyl) (4-tert-butylcyclohexyl)oxycarbonyloxy carbonate Chemical compound C1CC(C(C)(C)C)CCC1OC(=O)OOC(=O)OC1CCC(C(C)(C)C)CC1 NOBYOEQUFMGXBP-UHFFFAOYSA-N 0.000 description 1
- 229920002818 (Hydroxyethyl)methacrylate Polymers 0.000 description 1
- BEQKKZICTDFVMG-UHFFFAOYSA-N 1,2,3,4,6-pentaoxepane-5,7-dione Chemical compound O=C1OOOOC(=O)O1 BEQKKZICTDFVMG-UHFFFAOYSA-N 0.000 description 1
- JIHQDMXYYFUGFV-UHFFFAOYSA-N 1,3,5-triazine Chemical compound C1=NC=NC=N1 JIHQDMXYYFUGFV-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- BJELTSYBAHKXRW-UHFFFAOYSA-N 2,4,6-triallyloxy-1,3,5-triazine Chemical compound C=CCOC1=NC(OCC=C)=NC(OCC=C)=N1 BJELTSYBAHKXRW-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- MIEUQGPIBQNSDB-UHFFFAOYSA-N 2-(2-methylprop-2-enoyloxy)ethanesulfonic acid;sodium Chemical compound [Na].CC(=C)C(=O)OCCS(O)(=O)=O MIEUQGPIBQNSDB-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- BQZJOQXSCSZQPS-UHFFFAOYSA-N 2-methoxy-1,2-diphenylethanone Chemical compound C=1C=CC=CC=1C(OC)C(=O)C1=CC=CC=C1 BQZJOQXSCSZQPS-UHFFFAOYSA-N 0.000 description 1
- RPBWMJBZQXCSFW-UHFFFAOYSA-N 2-methylpropanoyl 2-methylpropaneperoxoate Chemical compound CC(C)C(=O)OOC(=O)C(C)C RPBWMJBZQXCSFW-UHFFFAOYSA-N 0.000 description 1
- AGBXYHCHUYARJY-UHFFFAOYSA-N 2-phenylethenesulfonic acid Chemical compound OS(=O)(=O)C=CC1=CC=CC=C1 AGBXYHCHUYARJY-UHFFFAOYSA-N 0.000 description 1
- KGIGUEBEKRSTEW-UHFFFAOYSA-N 2-vinylpyridine Chemical compound C=CC1=CC=CC=N1 KGIGUEBEKRSTEW-UHFFFAOYSA-N 0.000 description 1
- YHQXBTXEYZIYOV-UHFFFAOYSA-N 3-methylbut-1-ene Chemical compound CC(C)C=C YHQXBTXEYZIYOV-UHFFFAOYSA-N 0.000 description 1
- WHNPOQXWAMXPTA-UHFFFAOYSA-N 3-methylbut-2-enamide Chemical compound CC(C)=CC(N)=O WHNPOQXWAMXPTA-UHFFFAOYSA-N 0.000 description 1
- MKTOIPPVFPJEQO-UHFFFAOYSA-N 4-(3-carboxypropanoylperoxy)-4-oxobutanoic acid Chemical compound OC(=O)CCC(=O)OOC(=O)CCC(O)=O MKTOIPPVFPJEQO-UHFFFAOYSA-N 0.000 description 1
- UGVRJVHOJNYEHR-UHFFFAOYSA-N 4-chlorobenzophenone Chemical compound C1=CC(Cl)=CC=C1C(=O)C1=CC=CC=C1 UGVRJVHOJNYEHR-UHFFFAOYSA-N 0.000 description 1
- QSJXEFYPDANLFS-UHFFFAOYSA-N Diacetyl Chemical group CC(=O)C(C)=O QSJXEFYPDANLFS-UHFFFAOYSA-N 0.000 description 1
- 239000004641 Diallyl-phthalate Substances 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- WOBHKFSMXKNTIM-UHFFFAOYSA-N Hydroxyethyl methacrylate Chemical compound CC(=C)C(=O)OCCO WOBHKFSMXKNTIM-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- NQSMEZJWJJVYOI-UHFFFAOYSA-N Methyl 2-benzoylbenzoate Chemical compound COC(=O)C1=CC=CC=C1C(=O)C1=CC=CC=C1 NQSMEZJWJJVYOI-UHFFFAOYSA-N 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
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium peroxydisulfate Substances [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 1
- VAZSKTXWXKYQJF-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)OOS([O-])=O VAZSKTXWXKYQJF-UHFFFAOYSA-N 0.000 description 1
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 1
- PYKYMHQGRFAEBM-UHFFFAOYSA-N anthraquinone Natural products CCC(=O)c1c(O)c2C(=O)C3C(C=CC=C3O)C(=O)c2cc1CC(=O)OC PYKYMHQGRFAEBM-UHFFFAOYSA-N 0.000 description 1
- 150000004056 anthraquinones Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- RWCCWEUUXYIKHB-UHFFFAOYSA-N benzophenone Chemical compound C=1C=CC=CC=1C(=O)C1=CC=CC=C1 RWCCWEUUXYIKHB-UHFFFAOYSA-N 0.000 description 1
- 239000012965 benzophenone Substances 0.000 description 1
- QUDWYFHPNIMBFC-UHFFFAOYSA-N bis(prop-2-enyl) benzene-1,2-dicarboxylate Chemical compound C=CCOC(=O)C1=CC=CC=C1C(=O)OCC=C QUDWYFHPNIMBFC-UHFFFAOYSA-N 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- CDQSJQSWAWPGKG-UHFFFAOYSA-N butane-1,1-diol Chemical compound CCCC(O)O CDQSJQSWAWPGKG-UHFFFAOYSA-N 0.000 description 1
- IWTBWSGPDGPTIB-UHFFFAOYSA-N butanoyl butaneperoxoate Chemical compound CCCC(=O)OOC(=O)CCC IWTBWSGPDGPTIB-UHFFFAOYSA-N 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011549 displacement method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000000921 elemental analysis Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- YLQWCDOCJODRMT-UHFFFAOYSA-N fluoren-9-one Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3C2=C1 YLQWCDOCJODRMT-UHFFFAOYSA-N 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- ACCCMOQWYVYDOT-UHFFFAOYSA-N hexane-1,1-diol Chemical compound CCCCCC(O)O ACCCMOQWYVYDOT-UHFFFAOYSA-N 0.000 description 1
- VLAGSAGYAIGJSU-UHFFFAOYSA-N hexanoyl hexaneperoxoate Chemical compound CCCCCC(=O)OOC(=O)CCCCC VLAGSAGYAIGJSU-UHFFFAOYSA-N 0.000 description 1
- 238000007602 hot air drying Methods 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- XJRBAMWJDBPFIM-UHFFFAOYSA-N methyl vinyl ether Chemical compound COC=C XJRBAMWJDBPFIM-UHFFFAOYSA-N 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 150000002829 nitrogen Chemical class 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229940059574 pentaerithrityl Drugs 0.000 description 1
- WXZMFSXDPGVJKK-UHFFFAOYSA-N pentaerythritol Chemical compound OCC(CO)(CO)CO WXZMFSXDPGVJKK-UHFFFAOYSA-N 0.000 description 1
- JRKICGRDRMAZLK-UHFFFAOYSA-L persulfate group Chemical group S(=O)(=O)([O-])OOS(=O)(=O)[O-] JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 description 1
- 238000009832 plasma treatment Methods 0.000 description 1
- 239000002685 polymerization catalyst Substances 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- KOPQZJAYZFAPBC-UHFFFAOYSA-N propanoyl propaneperoxoate Chemical compound CCC(=O)OOC(=O)CC KOPQZJAYZFAPBC-UHFFFAOYSA-N 0.000 description 1
- 239000007870 radical polymerization initiator Substances 0.000 description 1
- 239000012966 redox initiator Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- MNCGMVDMOKPCSQ-UHFFFAOYSA-M sodium;2-phenylethenesulfonate Chemical compound [Na+].[O-]S(=O)(=O)C=CC1=CC=CC=C1 MNCGMVDMOKPCSQ-UHFFFAOYSA-M 0.000 description 1
- 239000012086 standard solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000008400 supply water Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- QXJQHYBHAIHNGG-UHFFFAOYSA-N trimethylolethane Chemical compound OCC(C)(CO)CO QXJQHYBHAIHNGG-UHFFFAOYSA-N 0.000 description 1
- 229910002007 uranyl nitrate Inorganic materials 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0088—Physical treatment with compounds, e.g. swelling, coating or impregnation
-
- 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
- B01D69/12—Composite membranes; Ultra-thin membranes
- B01D69/125—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/36—After-treatment
- C08J9/40—Impregnation
Description
〔産業上の利用分野〕
本発明は水処理や血液浄化等の分野で使用され
る多孔質膜及びその製造方法に関し、更に詳しく
は細孔表面が親水性の重合体で被覆されてなるポ
リオレフイン系多孔質膜及びその製造方法に関す
る。
〔従来の技術〕
ポリオレフイン多孔質膜は機械的性質や耐薬品
性が優れているためにその適用分野が急速に拡大
している。しかし、ポリオレフイン多孔質膜は疎
水性であるのでそのままでは水を透過させること
が難しく、水を始めとする親水性液体を透過させ
るために親水化処理が必要である。ポリオレフイ
ンの表面改質による親水化法については種々の方
法が検討されているが、表面形状が複雑な多孔質
膜の親水化に対して表面が滑らかなフイルム状物
等の親水化法を単純に適用することは出来ない。
ポリオレフイン多孔質膜の親水化法としては、
水との相溶性が良好なアルコールやケトン等の有
機溶剤によつてポリオレフイン多孔質膜の微細孔
部分を含めた表面全体を湿潤処理した後、該有機
溶剤を水で置換する有機溶剤湿潤・水置換法、ポ
リエチレングリコールや界面活性剤等の親水性物
質を多孔質膜の表面に吸着させて多孔質膜に親水
性を付与する物理的吸着法（特開昭54−153872
号、特開昭59−24732号）、あるいは親水性単量体
を多孔質フイルムの表面に保持させた状態で放射
線を照射する方法（特開昭56−38333号）が疎水
性樹脂多孔性構造物に水溶性高分子や界面活性剤
を含浸させた状態でプラズマ処理する方法（特開
昭56−157437号）等の化学的表面変性法が知られ
ている。
〔発明が解決しようとする問題点〕
しかし、有機溶剤湿潤・水置換法では保存中や
使用中に一旦細孔内の水が抜けるとその部分は疎
水性に戻り水を透過できなくなるので、多孔質膜
の周囲に常時水を充たしておくことが必要であ
り、取り扱いが煩雑である。物理的吸着法は操作
は簡単であるが、長時間に亘つて使用しているう
ちに該親水性物質が脱離するので必ずしも十分な
親水化法であるとは言えない。また従来の化学的
表面変性法では放射線を照射する方法及びプラズ
マ処理する方法のいずれの場合も、膜厚方向の均
一な親水化が難しく、膜が厚い場合や膜が中空糸
状である場合に膜厚方向の全体に亘つてほぼ均一
に親水化処理しようとすると多孔質膜基質の損
傷、機械的強度の低下が避けられない点等が問題
であつた。
本発明の目的は、上記従来技術の問題点を解消
し、ポリオレフイン多孔質膜の細孔表面上に親水
性の重合体が強固に保持されてなる多孔質膜及び
その製造方法を提供することにある。
〔問題点を解決するための手段〕
本発明の要旨は、ジアセトンアクリルアミドと
架橋性モノマーを含むモノマー類からなる親水性
架橋重合体をポリオレフイン多孔質膜の少なくと
も一部の細孔表面上に保持させてなる親水化多孔
質膜にあり、更に、ジアセトンアクリルアミドと
架橋性モノマーを含むモノマー類をポリオレフイ
ン多孔質膜の少なくとも一部の細孔表面上に保持
させた状態で加熱重合させることを特徴とする親
水化多孔質膜の製造方法にある。
本発明のポリオレフイン多孔質膜を構成するポ
リオレフイン素材としてはエチレン、プロピレ
ン、４−メチル−１−ペンテン、および３−メチ
ル−１−ブテンからなる群から選ばれる一種以上
の単量体を主成分（80wt％以上）とする重合体
または共重合体あるいはこれらのフツ素化物等を
挙げることができる。該多孔質膜としては中空糸
膜、平膜、管状膜等の任意の形態のものを用いる
ことができ、また用途に応じて種々の細孔径のも
のを使用することができるが、好ましい例とし
て、膜厚がおよそ20〜200μｍ程度、空孔率がお
よそ20〜90％程度、アルコール親水化法での水透
過率が0.001〜10／m2・hr・mmHg程度、細孔径
が0.01〜5μｍ程度のものを挙げることができる。
ポリオレフイン多孔質膜の細孔構造としては種々
のものがあるが、その中でも空孔率が大きくて目
詰まりによる性能低下が少ないという点から延伸
法によつて得られるポリオレフイン多孔質膜が好
ましく用いられる。延伸法による多孔質膜とは、
ミクロフイブリルと結節部とによつて形成される
スリツト状の微小空間（空孔）が３次元的に相互
に連通した細孔構造を有する多孔質膜であり、た
とえば特公昭56−52123号公報、特開昭57−42919
号公報等に記載された方法によつて製造すること
ができる。
又、多孔質膜の形態としては単位容積当たりの
膜面積が大きいことから中空糸状のものが好まし
く用いられる。
本発明の多孔質膜において親水性架橋重合体が
保持されるポリオレフイン多孔質膜の少なくとも
一部の細孔表面とは、細孔表面の一部あるいは全
部をいう。
即ち、通常使用される膜間差圧によつて多孔質
膜の細孔部分を水が通過して、使用に支障がない
程度の透過流量を得るのに十分な程度の細孔表面
に該重合体が保持されていればよく、必ずしも細
孔表面の全部が該重合体で被覆されている必要は
ない。また多孔質膜の外表面には該重合体が保持
されていてもいなくても良い。
保持させてなるとは保存中や使用中に容易に脱
離しない程度に該重合体が該細孔表面に強固に結
合ないし密着されていることをいい、該重合体が
該細孔表面に化学結合していてもよく、該重合体
が微細孔部分にアンカー効果によつて密着されて
いてもよく、また、スリツト状の細孔を形成する
ミクロフイブリルや結節部等を包むようにして該
重合体が密着架橋されていてもよく、これらの保
持状態が混存していてもよい。
このようにポリオレフイン多孔質膜の細孔表面
への親水性架橋重合体の保持状態としては任意の
状態をとりうるが、該重合体を化学結合させるこ
となくアンカー効果や密着架橋等の如く物理的に
該細孔表面上に保持させた親水化多孔質膜は、基
材のポリオレフイン多孔質膜と比較して機械的強
度の劣化や細孔構造の変化が殆んどないので特に
好ましいものである。
本発明においては、ポリオレフイン多孔質膜の
細孔表面上にジアセトンアクリルアミドと架橋性
モノマーを含むモノマー類からなる親水性架橋重
合体を保持させるが、これは他の重合体と比較し
て該重合体が、(1)ポリオレフインに対して強固に
保持できること、(2)ポリオレフイン多孔質膜の細
孔表面のほぼ全体に亘つてほぼ均一に保持できる
こと、(3)適度な親水性を有していること、及び(4)
実質的に水不溶性であることによる。
ジアセトンアクリルアミドと架橋性モノマーを
含有するモノマー類からなる親水性架橋重合体と
は、モノマー成分としてのジアセトンアクリルア
ミドを50重量％以上含有し、かつ架橋性モノマー
を含有する系からなる架橋重合体であつて、モノ
マー成分としてはこれらの他に非架橋性モノマー
が含まれていてもよい。
架橋性モノマーとしては、ジアセトンアクリル
アミドと共重合可能なビニル結合やアリル結合等
の重合性不飽和結合を２個以上有するモノマー、
あるいは前記重合性不飽和結合を１個有しかつ縮
合反応等によつて化学結合を生成可能な官能基を
少なくとも１個有するモノマーであつてジアセト
ンアクリルアミドと共通の良溶媒を有するモノマ
ーを挙げることができ、その例として、Ｎ，
N′−メチレンビスアクリルアミド、Ｎ−ヒドロ
キシメチルアクリルアミド、Ｎ−ヒドロキシメチ
ルメタクリルアミド、トリアリルシアヌレート、
トリアリルイソシアヌレート、ジビニルベンゼ
ン、２，２−ビス（４−メタクリロイロキシポリ
エトキシフエニル）プロパン、エチレンジ（メ
タ）アクリレート、ポリエチレングリコールジ
（メタ）アクリレート、トリメチロールプロパン
トリ（メタ）アクリレート、ペンタエリスリトー
ルテトラ（メタ）アクリレート、トリメチロール
エタントリ（メタ）アクリレート、ブタンジオー
ルジ（メタ）アクリレート、ヘキサンジオールジ
（メタ）アクリレート、ジアリルフタレート、１，
３，５−トリアクリロイルヘキサンヒドロキシ−
ｓ−トリアジン等を挙げることができる。
又、非架橋性モノマーとしては、ジアセトンア
クリルアミドと共重合可能なビニル結合やアリル
結合等の重合性不飽和結合を１個有するモノマー
であつて、ジアセトンアクリルアミドと共通の良
溶媒を有するモノマーを挙げることができ、その
例としてジメチルアクリルアミド、ビニルピロリ
ドン、アクリル酸、メタクリル酸、ヒドロキシエ
チルメタクリレート、スチレンスルホン酸、スチ
レンスルホン酸ナトリウム、スルホエチルメタク
リル酸ナトリウム、ビニルピリジン、ビニルメチ
ルエーテル等を挙げることができる。
以下、このような架橋性モノマーと非架橋性モ
ノマーを合わせて共重合性モノマーと総称する。
親水性架橋重合体を生成するジアセトンアクリ
ルアミドと共重合性モノマーの組成比としてはジ
アセトンアクリルアミド100重量部に対し共重合
性モノマーが、0.5〜100重量部程度であることが
好ましい。
本発明においてはポリオレフイン多孔質膜の細
孔表面上に保持される重合体が架橋重合体である
ために、該重合体は水中での膨潤の程度が小さく
て細孔を閉塞する惧れがなく、又、重合体の安定
性が良好であつて水中での溶出成分の量が著しく
少ないという利点がある。従つて、該多孔質膜は
微量の溶出成分が問題となる水処理分野や血液浄
化分野等において有効である。
これに対し、架橋構造を有していないジアセト
ンアクリルアミド系重合体は水中において膨潤し
て細孔を閉塞し、又、微量ではあるが水に溶解し
て溶出成分となるので、このような重合体を保持
させた多孔質膜は使用時において種々の問題を生
じさせる惧れがある。
又、重合体の親水性の程度が大きい程、多孔質
膜の透水性能が良好であり、使用開始時において
短時間で膜面全体から水が均一に透過するので、
親水性架橋重合体を生成する架橋性モノマーとし
ては、親水性の程度が充分な水溶性の架橋性モノ
マーであることが好ましい。
このような水溶性の架橋性モノマーとは、30℃
の水に対する溶解度が1.0ｇ／dl以上である架橋
性モノマーであり、その例としてＮ−ヒドロキシ
メチルアクリルアミド、Ｎ−ヒドロキシメチルメ
タクリルアミド、Ｎ，N′−メチレンビスアクリ
ルアミド等を挙げることができる。
本発明のポリオレフイン多孔質膜の少なくとも
一部の細孔表面に保持されてなる親水性架橋重合
体の量は、ポリオレフイン多孔質膜の空孔率や細
孔径にも依存するが、ポリオレフイン多孔質膜の
重量に対しおよそ0.5〜100重量％程度であること
が好ましい。重合体の保持量がこの範囲より少な
いと多孔質膜に充分な親水性を付与することがで
きず、又、この範囲を越えても多孔質膜の親水性
はさらに大きくは向上せず、むしろ細孔容積が減
少して透水性能が低下する場合がある。重合体の
保持量は0.5〜50重量％程度であることがより好
ましく、１〜30重量％程度であることが特に好ま
しい。
以下、本発明の親水化多孔質膜の製造方法につ
いて説明する。
本発明において親水性架橋重合体をポリオレフ
イン多孔質膜の細孔表面上に保持させる方法とし
ては、種々の方法を採用することができる。例え
ば、有機溶剤または水等の適当な溶媒にジアセト
ンアクリルアミド及び前述の共重合性モノマー
（以下これらを「モノマー類」という）や重合開
始剤を溶解させた溶液を調製し、ポリオレフイン
多孔質膜をその溶液中に浸漬する方法、あるいは
ポリオレフイン多孔質膜で膜モジユールを製作し
た後この溶液を多孔質膜内に圧入する方法等によ
り該溶液を多孔質膜に含浸させた後、溶媒を揮発
除去させる方法が採用できる。溶媒で希釈したモ
ノマー類の溶液を用いることによつて多孔質膜の
細孔を塞ぐことなく多孔質膜の全体にわたつてモ
ノマー類をほぼ均一に付着させることができる。
また、該溶液のモノマー類の濃度や該溶液の含浸
時間を変化させることによりモノマー類の付着量
が調整できる。
このようにして該多孔質膜の少なくとも一部の
細孔表面上にこれらのモノマー類を保持させた状
態で溶媒を除去し次いで重合させることによりポ
リオレフイン多孔質膜の少なくとも一部の細孔表
面上に親水性架橋重合体を保持させることができ
る。
前記の溶液を調製する場合の溶媒としては、モ
ノマー類よりも沸点が低く、かつモノマー類を溶
解することが可能な水又は有機溶剤が用いられる
が、重合開始剤を添加する場合は重合開始剤をも
溶解できる溶媒を用いることが好ましい。
このような有機溶剤としてはメタノール、エタ
ノール、プロパノール、イソプロパノール等のア
ルコール類、アセトン、メチルエチルケトン、メ
チルイソブチルケトン等のケトン類、テトラヒド
ロフラン、ジオキサン等のエーテル類、酢酸エチ
ル等を挙げることができる。有機溶媒の沸点は特
に限定されないが、重合工程前の溶媒除去が容易
であることを考慮するとおよそ100℃以下である
ことが好ましく、およそ80℃以下であることがよ
り好ましい。
ポリオレフイン多孔質膜の表面は疎水性である
ので特に溶媒として水を用いる場合はモノマー類
を含む水溶液が細孔内に浸透する際、モノマー類
が細孔表面においてその親水性基を外側に向けて
配向吸着されやすいので重合によつてこの状態を
固定すれば極めて効率的に親水性を付与すること
ができる。溶媒として水を用いる場合は多孔質膜
を直接溶液に接触させることもできるが、予じめ
アルコール類やケトン類等で多孔質膜の細孔表面
を湿潤処理した後前記溶液を接触させることもで
きる。
また溶媒として有機溶剤を用いる場合は溶液が
短時間でポリオレフイン多孔質膜の細孔内に浸透
すること、及び該細孔内からの溶媒除去が容易で
ある等の利点がある。
尚、前記の配向吸着を利用しないでモノマー類
が細孔表面において無秩序に配向した状態で重合
が行なわれた場合においても、形成された親水性
架橋重合体はポリオレフインと比較すると親水性
の程度が大きいので、該重合体が保持されている
細孔表面は、該重合体が保持されていない細孔表
面と比較すると相対的に親水性を有しており、親
水性が付与されたポリオレフイン多孔質膜を得る
ことができる。
重合開始剤の要否は重合方法に依存し、熱重合
法や光重合法の場合は重合開始剤が用いられる
が、放射線重合法の場合は重合開始剤を必要とし
ない。
熱重合法の場合はラジカル重合開始剤として知
られている種々の過酸化物、アゾ系化合物、レド
ツクス系開始剤を用いることができる。その例と
して、２，2′−アゾビスイソブチロニトリル、
２，2′−アゾビスシクロプロピルプロピオニトリ
ル、２，2′−アゾビス−２，４−ジメチルバレロ
ニトリル、２，2′−アゾビス−２，３，３−トリ
メチルブチロニトリル等のアゾ系化合物、アセチ
ルパーオキサイド、プロピオニルパーオキサイ
ド、ブチリルパーオキサイド、イソブチリルパー
オキサイド、サクシニルパーオキサイド、ベンゾ
イルパーオキサイド、ベイゾイルイソブチリルパ
ーオキサイド、β−アリロキシプロピオニルパー
オキサイド、ヘキサノイルパーオキサイド、３−
ブロモベンゾイルパーオキサイド、ビス−（４−
ｔ−ブチルシクロヘキシル）パーオキシジカーボ
ネート等の過酸化物、過硫酸カリウム、過硫酸ア
ンモニウム等の過硫酸塩等を挙げることが出来
る。
特に溶媒に水を用いた場合には水溶性の重合開
始剤例えばアゾビスイソブチラミジン、４，4′−
アゾビス−４−シアノペンタノイツクアシドが好
ましいが、モノマー類自体が界面活性を有するた
め水不溶性の重合開始剤であつても水中に分散で
きるので、前記の水不溶性重合開始剤を用いるこ
ともできる。
光重合法の場合の重合開始剤としては、ベンゾ
フエノン、ベンゾインメチルエーテル、ベンジル
ジメチルケタール、フルオレノン、４−ブロモベ
ンゾフエノン、４−クロロベンゾフエノン、メチ
ルｏ−ベンゾイルベンゾエート、ベンゾイルパー
オキサイド、アントラキノン、ビアセチル、硝酸
ウラニル等を挙げることができる。またこれらを
適当に組合わせて使用することも可能である。
溶液中におけるモノマー類と溶媒との組成は溶
媒の種類や目標とする重合体の保持量等を考慮し
て適宜選択すればよく、モノマー類100重量部に
対して溶媒は50〜10000重量部程度であればよく
200〜5000重量部程度であることがより好ましい。
モノマー類中のジアセトンアクリルアミドと共
重合性モノマーとの組成比は、共重合性モノマー
の親水性の程度や目標とする共重合比や架橋密度
等を考慮して適宜選択すればよく、ジアセトンア
クリルアミド100重量部に対して共重合性モノマ
ーは0.5〜100重量部程度であればよく、１〜90重
量部程度であることがより好ましい。
又、重合開始剤は、モノマー類100重量部に対
して0.001〜100重量部程度であればよく、0.01〜
30重量部程度であることがより好ましく、0.1〜
20重量部程度であることが特に好ましい。
モノマー類に対して溶媒の量が前記範囲を越え
ると多孔質膜の細孔表面に保持されるモノマー類
の量が少なすぎて充分な量の重合体を保持させる
ことができず、また前記範囲より少ないと、重合
体の保持量のコントロールが難しく、また細孔表
面や細孔内部に保持される重合体の量が多くなり
すぎて細孔の閉塞を招くことがあるので好ましく
ない。
これらの溶液を用いてポリオレフイン多孔質膜
に対して浸漬処理または圧入処理する際の浸漬時
間または圧入時間およそ0.5秒〜30分間程度であ
り、ポリオレフイン多孔質膜に対する濡れ特性が
良好な溶液を用いた場合程、より短時間で実施す
ることができる。
このようにしてモノマー類または更に重合開始
剤を少なくとも一部の細孔表面上に保持されたポ
リオレフイン多孔質膜は周囲の余分な液を除去さ
れ、更に必要に応じて細孔内部の溶媒を蒸発除去
された後、次の重合工程に移される。
溶媒の蒸発除去時の温度が高すぎると溶媒が残
留している間に重合が部分的に進行し、多孔質膜
の細孔表面でない細孔内部で重合が起こり、その
結果一部の細孔が閉塞されることがあるので好ま
しくなく、これを考慮すると溶媒除去時の温度は
およそ10〜40℃程度であることが好ましい。
本発明においては熱重合法、光重合法、放射線
重合法、プラズマ重合法等の重合方法を採用する
ことができる。
熱重合法の場合、重合温度は前記重合触媒の分
解温度以上であり、またポリオレフイン多孔質膜
の膜構造を変化させることなくかつ膜基質を損傷
しない程度以下の温度とすることが望ましく、通
常は30〜100℃程度の温度を採用することができ
る。また加熱時間は重合開始剤の種類と加熱温度
に依存するがバツチ法では通常は１分間〜５時間
程度より好ましくは15分間〜３時間程度である。
又、連続法では熱伝達効率が高いためにより短時
間で重合でき、加熱時間は通常10秒間〜60分間程
度より好ましくは20秒間〜10分間程度である。
光重合法の場合、光照射の光源としては紫外線
や可視光線を用いることができ、紫外線源として
は低圧水銀灯、高圧水銀灯、キセノン灯、アーク
灯等を用いることができる。
光照射条件としてはたとえば水銀灯を光源とし
て用いる場合は入力を10〜300W／cm程度とし10
〜50cm程度の距離から0.5〜300秒間程度照射する
ことによつて0.001〜10joule／cm2程度より好まし
くは0.05〜1joule／cm2程度のエネルギーを照射す
る条件が採用される。
低照射強度では十分な親水化を達成することが
困難であり、また高照射強度ではポリオレフイン
多孔質膜の損傷が大きいので膜厚等を考慮して適
当な光照射条件を慎重に選定することが好まし
い。
放射線重合の場合はたとえば電子線照射装置を
用い、120℃以下より好ましくは100℃以下の温度
にて電子線を10〜50M rad程度照射することに
よつて実施することができる。
尚、これらの重合の際、雰囲気内に酸素が存存
すると重合反応が著しく阻害されるので窒素雰囲
気等の不活性ガス雰囲気、あるいは真空等の実質
的に酸素が存在しない状態にて重合させることが
望ましい。
架橋性モノマーを用いて親水性架橋重合体を生
成させる場合、架橋反応は重合反応と同時に行な
わせてもよく、いつたん共重合体を生成させた後
に架橋させてもよい。又、縮合による架橋反応
は、重合反応熱を利用して行なつてもよく、加熱
によつて行なつてもよい。
特に縮合による架橋反応を利用する場合は、予
じめ調製したジアセトンアクリルアミドと架橋性
モノマーとの未架橋の共重合体を溶液に溶解し次
いでポリオレフイン多孔質膜の細孔表面上に保持
させ、その状態で架橋反応させる方法を用いても
よい。この場合未架橋の共重合体の分子量はおよ
そ１〜50万程度であることが好ましく分子量が大
きすぎると該共重合体をポリオレフイン多孔質膜
の細孔内部に侵入させることが困難であり好まし
くない。分子量は５〜30万程度であることがより
好ましい。
本発明においては上述のように種々の重合法を
採用できるが、熱エネルギーによる方法が最も好
ましい。熱エネルギーを利用する場合は多孔質膜
の細孔部分まで均一温度に加熱することができる
のでモノマー類が保持されている全ての細孔表面
上において均一に重合することができ、かつ重合
温度を適度に設定することによつて膜の構造を変
化させることなくかつ膜基質を劣化させることな
く重合することができる利点がある。一方、光エ
ネルギーを利用する場合は光の散乱によつて多孔
質膜の細孔部分まで光が十分に到達しにくいとい
う問題及び光の照射強度を上げると膜基質の劣化
が進行しやすいという問題があり、また放射線エ
ネルギーを利用する場合も膜基質の劣化が進行し
やすいという問題がある。従つてこれらの重合方
法を採用する場合は膜基質を劣化させないような
重合条件を慎重に選定することが必要である。
ポリオレフイン多孔質膜の細孔表面上に保持さ
れたモノマー類や前記の未架橋の共重合体はこれ
らの重合手法によつて多孔質膜表面上において重
合、架橋するので、多孔質膜の細孔表面の少なく
ともその一部はこれらの重合体によつて被覆され
る。
親水性架橋重合体が生成された後は、適当な溶
媒を用い浸漬法や圧入法によつて多孔質膜細孔表
面の周囲に存在する未反応モノマーや遊離したポ
リマー等の不要成分を除去することが望ましい。
溶媒としては水、有機溶剤、あるいはそれらの混
合溶媒を単独または併用して用いることができ
る。
本発明の親水化多孔質膜はこのようにして製造
することができるが、特に好ましい方法としてジ
アセトンアクリルアミドと水溶性の架橋性モノマ
ーを含むモノマー類及び重合開始剤をポリオレフ
イン多孔質膜の少なくとも一部の細孔表面上に保
持させた状態で加熱重合させる方法を挙げること
ができる。
共重合性モノマーとして水溶性の架橋性モノマ
ーを用いると重合体の水中での膨潤が抑制され、
溶出成分の量を一段と減少させることができると
共に親水化多孔質膜は優れた透水性能を発揮す
る。
又、加熱重合法によつて製造される親水化多孔
質膜は、膜厚方向における重合体の保持状態に斑
がなく、膜基質の損傷が殆んどないという特徴を
有している。
以上、各工程について別々に説明してきたが、
本発明においてはポリオレフイン多孔質膜の細孔
表面上へのモノマー類等の保持、溶媒除去、重
合、重合後の洗浄等をほぼ連続的に行なうことも
できる。
以下実施例により本発明を具体的に説明する。
尚、実施例においては、いずれも延伸法によつ
て得られるミクロフイブリルと結節部とで形成さ
れるスリツト状の空間（空孔）が３次元的に連通
したポリオレフイン多孔質膜を用い、該多孔質膜
の孔径は該スリツト状空間の幅の平均値と長さの
平均値とで表現した。
透水圧、アルコール親水化法での水透過率及び
重合体保持後の水透過率はそれぞれ有効膜面積が
163cm2の試験膜モジユールを用い次の方法によつ
て測定した。また重合体の保持量、結節強度及び
積算溶出率は次の方法によつて測定し、重合体に
よる細孔表面の被覆状態の評価は次の方法によつ
て実施した。
又、実施例で用いたＮ−ヒドロキシメチルアク
リルアミド、Ｎ，N′−メチレンビスアクリルア
ミド及びトリアリルイソシアヌレートの30℃の水
に対する溶解度はそれぞれ197ｇ／dl、３ｇ／dl
及び0.1ｇ／dlである。
(1) 透水圧：試験膜モジユールの一方（中空糸膜
の場合は中空糸の内側）から１分毎に0.1Kg／
cm2の割合で水圧を上げながら25℃の水を供給
し、積算透過水量が30mlと50mlになる時の水圧
を測定する。続いて横軸に水圧をまた縦軸に透
過水量をプロツトし、プロツトした２点を結ぶ
直線が横軸と交わる点の圧力値を求めその値を
透水圧とする。
(2) アルコール親水化法での水透過率：親水化処
理をしていない試験膜モジユールの一方（中空
糸膜の場合は中空糸膜の内側）からエタノール
を25ml／minの流量で15分間圧入して多孔質膜
の細孔内部まで充分にエタノールで湿潤させた
後、水を100ml／minの流量で15分間流し、細
孔内部に存在するエタノールを水で置換する。
続いて試験膜モジユールの一方（中空糸の場合
は中空糸の内側）から25℃の水を流して膜間差
圧が50mmHgにおける透過水量を測定し、その
値から水透過率（／m2・hr・mmHg）を求め
る。
(3) 重合体の保持量：元素分析法によつて窒素含
有量を測定し、この窒素が重合体のみに由来
し、モノマー組成比と同一組成比の重合体が形
成されているものと仮定し、ポリオレフイン多
孔質膜の単位重量に対して保持されている重合
体の重量％を算出する。
(4) 細孔表面の被覆状態の評価：JIS K6768
（1971）に記載の表面張力54dyn／cmのぬれ試
験用標準液（青色）中に多孔質膜を１分間浸漬
した後風乾し、該多孔質膜の横切断面を光学顕
微鏡によつて観察し着色された重合体の分布状
態を調べる。
(5) 結節強度：JIS L1013によつて多孔質中空糸
膜の結節強度を測定する。
(6) 積算溶出率：多孔質膜をその重量の10倍量の
65℃の温水中に浸漬し、一定時間毎に、その温
水中の全有機炭素量を測定する。この全有機炭
素量が前記(3)で仮定された組成比の重合体のみ
に由来するものと仮定して、積算溶出量を算出
し、溶出処理前の重合体保持量に対する積算溶
出率（重量％）を求める。
(7) 重合体保持後の水透過率：重合体を保持させ
た多孔質膜で製作した試験膜モジユールの一方
（中空糸膜の場合は中空糸膜の内側）から圧力
２Kg／cm2の水を３時間圧入した後、該試験膜モ
ジユールの一方から25℃の水を流して膜間差圧
が50mmHgにおける透過水量を測定し、その値
から水透過率（／m2・hr・mmHg）を求める。
実施例 １
スリツト状細孔の幅0.4μｍ、長さ1.8μｍ、空孔
率63％、膜厚70μｍ、内径270μｍ、結節強度394
ｇ／fil、透水圧11Kg／cm2、アルコール親水化法
による水透過率が1.1／m2・hr・mmHgであるポ
リエチレン多孔質中空糸膜をジアセトンアクリル
アミド100部、Ｎ−ヒドロキシメチルアクリルア
ミド５部、ベンゾイルパーオキサイド１部及びア
セトン1000部からなる処理溶液に10秒間浸漬した
後、窒素中にとり出し５分間風乾した。続いてこ
の多孔質膜を窒素雰囲気中において65℃で60分間
加熱処理し、ついで水／エタノール＝50／50（部）
混合溶媒に10分間浸漬し更に温水中で２分間超音
波洗浄することにより不要成分を洗浄除去した。
次に熱風乾燥により溶媒を除去し重合体が保持さ
れた多孔質膜を得た。
この多孔質膜の透水圧、水透過率、重合体の保
持量、結節強度、積算溶出率等を測定してその結
果を第１表に示した。
親水化多孔質膜の透水性能は良好であり、多孔
質膜の細孔表面のほぼ全面に亘つてほぼ均一に重
合体が保持されていた。また結節強度は良好であ
り元の多孔質膜と比較して機械的強度は低下して
いなかつた。積算溶出率の測定から24時間以降は
実質的に溶出成分がないことがわかつた。
実施例 ２〜４
架橋性モノマーとしてそれぞれ第１表に示す量
のＮ−ヒドロキシメチルアクリルアミドを使用
し、その他の条件は実施例１と同様にして多孔質
膜に重合体を保持させた。
このようにして得られた親水化多孔質膜の性能
を評価し、第１表の結果を得た。
実施例 ５
多孔質膜としてスリツト状細孔の幅0.2μｍ、長
さ0.7μｍ、空孔率45％、膜厚22μｍ、内径200μｍ、
透水圧12Kg／cm2、アルコール親水化法による水透
過率が0.54／m2・hr・mmHgのポリプロピレン
製多孔質中空糸膜を、処理溶液としてジアセトン
アクリルアミド100部、Ｎ，N′−メチレンビスア
クリルアミド５部及び２，2′−アゾビスイソブチ
ロニトリル５部及びアセトン800部からなる溶液
を用い、又熱処理条件を65℃で60分間とし、その
他は実施例１と同様にして重合体を保持させた多
孔質膜を得、その性能を評価し、第１表に示し
た。
細孔表面のほぼ全面に亘つてほぼ均一に重合体
が保持されていた。24時間以降は実質的に溶出成
分がないことがわかつた。
実施例 ６〜８
架橋性モノマーとしてそれぞれ第１表に示す量
のＮ，N′−メチレンビスアクリルアミドを使用
し、その他の条件は実施例５と同様にして多孔質
膜に重合体を保持させた。
このようにして得られた親水化多孔質膜の性能
を評価し、第１表の結果を得た。
実施例 ９
多孔質膜としてスリツト状細孔の幅0.8μｍ、長
さ3.0μｍ、空孔率70％、膜厚42μｍ、透水圧4.5
Kg／cm2、アルコール親水化法による水透過率が
3.5／m2・hr・mmHgのポリエチレン製多孔質平
膜を、処理溶液としてジアセトンアクリルアミド
100部、Ｎ−ヒドロキシメチルアクリルアミド５
部、ベンゾイルパーオキサイド10部及びメチルエ
チルケトン330部からなる溶液を用い、又熱処理
条件を60℃で60分間とし、その他は実施例１と同
様にして重合体を保持させた多孔質膜を得、その
性能を評価し第１表の結果を得た。
細孔表面のほぼ全面に亘つてほぼ均一に重合体
が保持されていた。２４時間以降は実質的に溶出
成分がないことがわかつた。
実施例 10〜12
架橋性モノマーとしてそれぞれ第１表に示す量
のＮ−ヒドロキシメチルアクリルアミドを使用
し、その他の条件は実施例９と同様にして多孔質
膜に重合体を保持させた。
このようにして得られた親水化多孔質膜の性能
を評価し、第１表の結果を得た。
実施例 13
架橋性モノマーとしてトリアリルイソシアヌレ
ート５部を使用し、その他の条件は実施例１と同
様にして多孔質膜に重合体を保持させた。
このようにして得られた親水化多孔質膜の性能
を評価し、第２表の結果を得た。重合体は細孔表
面のほぼ全面に亘つてほぼ均一に保持されてい
た。
実施例 14
架橋性モノマーとしてトリアリルイソシアヌレ
ート５部を使用し、その他の条件は実施例５と同
様にして多孔質膜に重合体を保持させた。
このようにして得られた多孔質膜の性能を評価
し、第２表の結果を得た。
実施例 15
ジアセトンアクリルアミド100部、ジビニルベ
ンゼン１部、ベンゾイルパーオキサイド0.3部、
メチルエチルケトン450部からなる溶液を用いて
浸漬時間を３秒間、熱重合条件を70℃で60分と
し、その他の条件は実施例５と全く同様にして重
合体を多孔質膜に保持させた。
この多孔質膜の性能を評価し、第２表の結果を
得た。多孔質膜の細孔表面にはほぼ全面に亘つて
ほぼ均一に重合体が保持されていた。積算溶出率
の測定から、24時間以降は実質的に溶出成分がな
いことがわかつた。
実施例 16
実施例９と同様のポリエチレン多孔質平膜を用
い、又、ジアセトンアクリルアミド100部、トリ
アリルイソシアヌレート５部、ベンゾイルパーオ
キサイド５部、アセトン330部からなる溶液を用
い、浸漬時間を３秒間、熱処理条件を60℃で30分
間としたこと以外は実施例９と同様にして本発明
の親水化多孔質膜を得た。又、その性能を評価し
第２表の結果を得た。
実施例 17
スリツト状細孔の幅0.2μｍ、長さ0.5μｍ、空孔
率43％、膜厚35μｍ、アルコール親水化法による
水透過率が0.2／m2・hr・mmHgであるポリ−４
−メチル−１−ペンテン多孔質平膜を用い、ベン
ゾイルパーオキサイドの量を0.5部、溶液中での
浸漬時間を３秒間、加熱重合条件を75℃で25分間
とする以外は実施例１と同様にして本発明の親水
化多孔質膜を得、その性能を評価して第２表の結
果を得た。該多孔質膜の細孔表面には、ほぼ全面
に亘つてほぼ均一に重合体が保持されていた。
実施例 18〜21
実施例１と同様のポリエチレン多孔質中空糸膜
を速度２ｍ／minで連続的に供給し、長さ10cmの
溶液槽中で浸漬処理し、直径２cm、長さ４ｍのパ
イプ１の中で付着液の除去及び乾燥を行ない、次
いで直径２cm、長さ３ｍのパイプ２の中で加熱し
モノマー類を重合させた。
溶液の組成はそれぞれジアセトンアクリルアミ
ド100部、第２表に示す量のＮ−ヒドロキシメチ
ルアクリルアミド、ビス−（４−ターシヤリーブ
チルシクロヘキシル）パーオキシジカーボネート
0.5部及びアセトン660部とした。パイプ１には常
温の窒素を、パイプ２の中には80℃の加熱窒素を
それぞれ３／minで流した。
続いてこの中空糸膜を水／エタノール＝50／50
（部）の混合溶媒を入れた長さ50cmの槽及び60℃
の温水をオーバーフローさせている長さ1.5ｍの
水槽を通過させて洗浄し、更に熱風雰囲気中で乾
燥することによつて本発明の親水化多孔質膜を得
た。
該多孔質膜の性能を評価し第２表の結果を得
た。これらの多孔質膜の細孔表面にはほぼ全面に
亘つてほぼ均一に重合体が保持されていた。
[Industrial Application Field] The present invention relates to a porous membrane used in fields such as water treatment and blood purification, and a method for producing the same, and more specifically to a porous membrane whose pore surface is coated with a hydrophilic polymer. The present invention relates to a porous membrane and a method for manufacturing the same. [Prior Art] Polyolefin porous membranes have excellent mechanical properties and chemical resistance, so the fields of their application are rapidly expanding. However, since polyolefin porous membranes are hydrophobic, it is difficult for water to pass through them as is, and a hydrophilic treatment is required to allow water and other hydrophilic liquids to pass through them. Various methods have been studied for making polyolefins hydrophilic by surface modification, but in contrast to making porous membranes with complex surface shapes hydrophilic, a simple method for making hydrophilic materials such as film-like materials with smooth surfaces has been proposed. It cannot be applied. As a method for making polyolefin porous membranes hydrophilic,
Organic solvent wetting/water treatment in which the entire surface of the porous polyolefin membrane, including the micropores, is wetted with an organic solvent such as alcohol or ketone that has good compatibility with water, and then the organic solvent is replaced with water. Substitution method, physical adsorption method in which a hydrophilic substance such as polyethylene glycol or a surfactant is adsorbed onto the surface of a porous membrane to impart hydrophilicity to the porous membrane (Japanese Patent Application Laid-open No. 153872-1982).
(Japanese Patent Application Laid-open No. 59-24732), or a method of irradiating a hydrophilic monomer with radiation on the surface of a porous film (Japanese Patent Application Laid-Open No. 56-38333) is a method for forming a porous structure of a hydrophobic resin. Chemical surface modification methods are known, such as a method in which an object is impregnated with a water-soluble polymer or a surfactant and then treated with plasma (Japanese Patent Application Laid-open No. 157437/1983). [Problem to be solved by the invention] However, in the organic solvent wetting/water displacement method, once the water in the pores is removed during storage or use, that part returns to hydrophobicity and cannot pass water. It is necessary to constantly fill the area around the membrane with water, which makes handling complicated. Although the physical adsorption method is easy to operate, it cannot necessarily be said to be a sufficient hydrophilization method because the hydrophilic substance is desorbed during long-term use. In addition, with conventional chemical surface modification methods, both irradiation with radiation and plasma treatment, it is difficult to make the film uniformly hydrophilic in the thickness direction. Attempts to make the film almost uniformly hydrophilic over the entire thickness direction have caused problems such as damage to the porous membrane matrix and unavoidable reduction in mechanical strength. An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a porous membrane in which a hydrophilic polymer is firmly held on the pore surface of a polyolefin porous membrane, and a method for producing the same. be. [Means for Solving the Problems] The gist of the present invention is to maintain a hydrophilic crosslinked polymer made of monomers containing diacetone acrylamide and a crosslinkable monomer on the surface of at least some pores of a porous polyolefin membrane. The polyolefin porous membrane is further characterized in that monomers including diacetone acrylamide and a crosslinking monomer are retained on the surface of at least some of the pores of the polyolefin porous membrane and then thermally polymerized. A method for producing a hydrophilized porous membrane is provided. The polyolefin material constituting the polyolefin porous membrane of the present invention is mainly composed of one or more monomers selected from the group consisting of ethylene, propylene, 4-methyl-1-pentene, and 3-methyl-1-butene. 80 wt% or more) or fluorinated products thereof. The porous membrane can be in any form such as a hollow fiber membrane, a flat membrane, or a tubular membrane, and can have various pore sizes depending on the application, but preferred examples include , membrane thickness is approximately 20 to 200 μm, porosity is approximately 20 to 90%, water permeability by alcohol hydrophilization method is approximately 0.001 to 10/ m2・hr・mmHg, and pore diameter is approximately 0.01 to 5 μm. I can list the following.
There are various types of pore structures for polyolefin porous membranes, but among them, polyolefin porous membranes obtained by a stretching method are preferably used because they have a large porosity and are less likely to deteriorate in performance due to clogging. . What is porous membrane made by stretching method?
It is a porous membrane having a pore structure in which slit-shaped micro spaces (pores) formed by microfibrils and nodules are three-dimensionally interconnected, and is disclosed in Japanese Patent Publication No. 56-52123, for example. , Japanese Patent Publication No. 57-42919
It can be manufactured by the method described in the above publication. Further, as the form of the porous membrane, a hollow fiber type is preferably used because the membrane area per unit volume is large. In the porous membrane of the present invention, the pore surface of at least a portion of the polyolefin porous membrane in which the hydrophilic crosslinked polymer is retained refers to a portion or all of the pore surface. In other words, water passes through the pores of the porous membrane due to the normally used transmembrane pressure, and the weight is applied to the pore surface to a sufficient degree to obtain a permeation flow rate that does not interfere with use. It is sufficient that the cohesion is maintained, and it is not necessarily necessary that the entire surface of the pores be covered with the polymer. Further, the polymer may or may not be retained on the outer surface of the porous membrane. Retained means that the polymer is firmly bonded or adhered to the pore surface to the extent that it does not easily detach during storage or use, and the polymer is chemically bonded to the pore surface. The polymer may be tightly attached to the micropores by an anchor effect, or the polymer may be wrapped around the microfibrils and knots forming the slit-like pores. It may be tightly crosslinked, or these retention states may coexist. In this way, the hydrophilic crosslinked polymer can be held in any state on the pore surface of the porous polyolefin membrane, but it is possible to maintain the hydrophilic crosslinked polymer on the pore surface of the polyolefin porous membrane in any desired state, but it is possible to maintain the hydrophilic crosslinked polymer on the pore surface of the polyolefin porous membrane in any desired state. The hydrophilized porous membrane held on the pore surface is particularly preferable because there is almost no deterioration in mechanical strength or change in pore structure compared to the polyolefin porous membrane used as the base material. . In the present invention, a hydrophilic crosslinked polymer made of monomers containing diacetone acrylamide and a crosslinking monomer is retained on the pore surface of a polyolefin porous membrane, but this polymer is Coalescence: (1) can be strongly held against polyolefin, (2) can be held almost uniformly over almost the entire pore surface of the polyolefin porous membrane, and (3) has appropriate hydrophilicity. and (4)
By being substantially water-insoluble. A hydrophilic crosslinked polymer consisting of monomers containing diacetone acrylamide and a crosslinking monomer is a crosslinked polymer consisting of a system containing 50% by weight or more of diacetone acrylamide as a monomer component and a crosslinking monomer. In addition to these monomer components, non-crosslinkable monomers may also be included. Examples of crosslinking monomers include monomers having two or more polymerizable unsaturated bonds such as vinyl bonds and allyl bonds that can be copolymerized with diacetone acrylamide;
Alternatively, monomers having one polymerizable unsaturated bond and at least one functional group capable of forming a chemical bond through a condensation reaction, etc., and having a good solvent in common with diacetone acrylamide may also be mentioned. As an example, N,
N'-methylenebisacrylamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, triallyl cyanurate,
Triallylisocyanurate, divinylbenzene, 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane, ethylene di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, penta Erythritol tetra(meth)acrylate, trimethylolethane tri(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diallyl phthalate, 1,
3,5-Triacryloylhexanehydroxy-
Examples include s-triazine. In addition, as the non-crosslinkable monomer, a monomer having one polymerizable unsaturated bond such as a vinyl bond or an allyl bond that can be copolymerized with diacetone acrylamide, and a monomer that has a good solvent in common with diacetone acrylamide is used. Examples include dimethylacrylamide, vinylpyrrolidone, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, styrene sulfonic acid, sodium styrene sulfonate, sodium sulfoethyl methacrylate, vinylpyridine, and vinyl methyl ether. can. Hereinafter, such crosslinkable monomers and non-crosslinkable monomers will be collectively referred to as copolymerizable monomers. The composition ratio of diacetone acrylamide and copolymerizable monomer to form a hydrophilic crosslinked polymer is preferably about 0.5 to 100 parts by weight of the copolymerizable monomer per 100 parts by weight of diacetone acrylamide. In the present invention, since the polymer retained on the pore surface of the polyolefin porous membrane is a crosslinked polymer, the degree of swelling of the polymer in water is small and there is no risk of clogging the pores. Furthermore, there are advantages in that the stability of the polymer is good and the amount of components eluted in water is extremely small. Therefore, the porous membrane is effective in the water treatment field, blood purification field, etc., where trace amounts of eluted components are a problem. On the other hand, diacetone acrylamide-based polymers that do not have a crosslinked structure swell in water and block pores, and also dissolve in water to become an eluted component, albeit in a small amount. Porous membranes that retain their cohesion may cause various problems during use. In addition, the greater the degree of hydrophilicity of the polymer, the better the water permeability of the porous membrane, and water permeates uniformly from the entire membrane surface in a short time at the beginning of use.
The crosslinkable monomer for forming the hydrophilic crosslinked polymer is preferably a water-soluble crosslinkable monomer having a sufficient degree of hydrophilicity. Such water-soluble crosslinking monomers are
A crosslinking monomer having a solubility in water of 1.0 g/dl or more, examples of which include N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N,N'-methylenebisacrylamide, and the like. The amount of the hydrophilic crosslinked polymer retained on the surface of at least some of the pores of the porous polyolefin membrane of the present invention depends on the porosity and pore diameter of the porous polyolefin membrane. The amount is preferably about 0.5 to 100% by weight based on the weight of . If the amount of polymer retained is less than this range, it will not be possible to impart sufficient hydrophilicity to the porous membrane, and even if it exceeds this range, the hydrophilicity of the porous membrane will not improve further; Pore volume may decrease and water permeability may decrease. The retained amount of the polymer is more preferably about 0.5 to 50% by weight, particularly preferably about 1 to 30% by weight. Hereinafter, a method for producing a hydrophilized porous membrane of the present invention will be explained. In the present invention, various methods can be employed to retain the hydrophilic crosslinked polymer on the pore surface of the porous polyolefin membrane. For example, a solution is prepared by dissolving diacetone acrylamide, the above-mentioned copolymerizable monomers (hereinafter referred to as "monomers"), and a polymerization initiator in an appropriate solvent such as an organic solvent or water, and a porous polyolefin membrane is formed. After the porous membrane is impregnated with the solution by immersion in the solution, or by press-fitting the solution into the porous membrane after manufacturing a membrane module with the porous polyolefin membrane, the solvent is removed by volatilization. method can be adopted. By using a solution of monomers diluted with a solvent, the monomers can be applied almost uniformly over the entire porous membrane without blocking the pores of the porous membrane.
Furthermore, the amount of monomers attached can be adjusted by changing the concentration of monomers in the solution and the impregnation time of the solution. In this way, the solvent is removed while these monomers are retained on at least some of the pore surfaces of the porous membrane, and then polymerized, so that the monomers are retained on at least some of the pore surfaces of the polyolefin porous membrane. can hold a hydrophilic crosslinked polymer. The solvent used to prepare the above solution is water or an organic solvent that has a boiling point lower than that of the monomers and is capable of dissolving the monomers, but if a polymerization initiator is added, the polymerization initiator It is preferable to use a solvent that can also dissolve. Examples of such organic solvents include alcohols such as methanol, ethanol, propanol and isopropanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethers such as tetrahydrofuran and dioxane, and ethyl acetate. The boiling point of the organic solvent is not particularly limited, but in view of ease of solvent removal before the polymerization step, it is preferably about 100°C or less, more preferably about 80°C or less. Since the surface of the polyolefin porous membrane is hydrophobic, especially when water is used as a solvent, when an aqueous solution containing monomers permeates into the pores, the monomers direct their hydrophilic groups outward on the pore surface. Since it is easily oriented and adsorbed, if this state is fixed through polymerization, hydrophilicity can be imparted extremely efficiently. When water is used as a solvent, the porous membrane can be brought into direct contact with the solution, but it is also possible to wet the pore surface of the porous membrane with an alcohol, ketone, etc. in advance and then bring the solution into contact with the solution. can. Further, when an organic solvent is used as the solvent, there are advantages such that the solution permeates into the pores of the polyolefin porous membrane in a short time and that the solvent can be easily removed from the pores. Furthermore, even when polymerization is carried out with the monomers oriented randomly on the pore surface without using the above-mentioned oriented adsorption, the hydrophilic crosslinked polymer formed has a lower degree of hydrophilicity than polyolefin. Because of its large size, the surface of the pores where the polymer is retained is relatively hydrophilic compared to the surface of the pores where the polymer is not retained. membrane can be obtained. The necessity of a polymerization initiator depends on the polymerization method; a polymerization initiator is used in thermal polymerization and photopolymerization, but no polymerization initiator is required in radiation polymerization. In the case of thermal polymerization, various peroxides, azo compounds, and redox initiators known as radical polymerization initiators can be used. Examples include 2,2'-azobisisobutyronitrile,
Azo compounds such as 2,2'-azobiscyclopropylpropionitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-2,3,3-trimethylbutyronitrile, etc. , acetyl peroxide, propionyl peroxide, butyryl peroxide, isobutyryl peroxide, succinyl peroxide, benzoyl peroxide, bezoylisobutyryl peroxide, β-allyloxypropionyl peroxide, hexanoyl peroxide, 3-
Bromobenzoyl peroxide, bis-(4-
Examples include peroxides such as t-butylcyclohexyl) peroxydicarbonate, and persulfates such as potassium persulfate and ammonium persulfate. Particularly when water is used as a solvent, water-soluble polymerization initiators such as azobisisobutyramidine, 4,4'-
Azobis-4-cyanopentanoic acid is preferred, but since the monomers themselves have surface activity, even water-insoluble polymerization initiators can be dispersed in water, so the water-insoluble polymerization initiators mentioned above can also be used. . In the case of photopolymerization, the polymerization initiator includes benzophenone, benzoin methyl ether, benzyl dimethyl ketal, fluorenone, 4-bromobenzophenone, 4-chlorobenzophenone, methyl o-benzoyl benzoate, benzoyl peroxide, anthraquinone, Biacetyl, uranyl nitrate, etc. can be mentioned. It is also possible to use a suitable combination of these. The composition of the monomers and solvent in the solution may be selected appropriately taking into account the type of solvent and the target amount of polymer retained, and the amount of solvent should be approximately 50 to 10,000 parts by weight per 100 parts by weight of monomers. It's fine if
More preferably, it is about 200 to 5000 parts by weight. The composition ratio of diacetone acrylamide and the copolymerizable monomer in the monomers may be selected appropriately taking into consideration the degree of hydrophilicity of the copolymerizable monomer, the target copolymerization ratio, the crosslinking density, etc. The amount of the copolymerizable monomer relative to 100 parts by weight of acrylamide may be about 0.5 to 100 parts by weight, and more preferably about 1 to 90 parts by weight. Further, the polymerization initiator may be about 0.001 to 100 parts by weight per 100 parts by weight of monomers, and may be about 0.01 to 100 parts by weight.
It is more preferably about 30 parts by weight, and 0.1 to
It is particularly preferable that the amount is about 20 parts by weight. If the amount of solvent relative to the monomers exceeds the above range, the amount of monomers retained on the pore surface of the porous membrane will be too small to retain a sufficient amount of polymer; If the amount is less, it is difficult to control the amount of polymer retained, and the amount of polymer retained on the pore surface or inside the pore becomes too large, which may lead to pore clogging, which is not preferable. The dipping time or press-fitting time when dipping or press-fitting a porous polyolefin membrane using these solutions is about 0.5 seconds to 30 minutes, and the solution used has good wetting properties for the porous polyolefin membrane. The more the case, the faster it can be done. In this way, the polyolefin porous membrane in which the monomers or even the polymerization initiator are retained on at least some of the pore surfaces is removed from the surrounding excess liquid, and if necessary, the solvent inside the pores is evaporated. After being removed, it is transferred to the next polymerization step. If the temperature during evaporation of the solvent is too high, polymerization will partially proceed while the solvent remains, and polymerization will occur inside the pores of the porous membrane instead of on the pore surface, resulting in some pores being removed. This is not preferable because the solvent may become clogged. Considering this, it is preferable that the temperature during solvent removal is approximately 10 to 40°C. In the present invention, polymerization methods such as thermal polymerization, photopolymerization, radiation polymerization, and plasma polymerization can be employed. In the case of thermal polymerization, the polymerization temperature is desirably higher than the decomposition temperature of the polymerization catalyst and lower than the temperature that does not change the membrane structure of the porous polyolefin membrane and damage the membrane substrate, and usually Temperatures of about 30 to 100°C can be employed. The heating time depends on the type of polymerization initiator and the heating temperature, but in the batch method it is usually about 1 minute to 5 hours, preferably about 15 minutes to 3 hours.
Further, in the continuous method, since the heat transfer efficiency is high, polymerization can be carried out in a shorter time, and the heating time is usually about 10 seconds to 60 minutes, more preferably about 20 seconds to 10 minutes. In the case of the photopolymerization method, ultraviolet light or visible light can be used as a light source for light irradiation, and a low-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, an arc lamp, etc. can be used as the ultraviolet light source. As for the light irradiation conditions, for example, when using a mercury lamp as a light source, the input should be about 10 to 300 W/cm10
Conditions are employed in which energy of about 0.001 to 10 joule/cm 2 , more preferably about 0.05 to 1 joule/cm 2 is irradiated by irradiating for about 0.5 to 300 seconds from a distance of about 50 cm. At low irradiation intensity, it is difficult to achieve sufficient hydrophilicity, and at high irradiation intensity, the polyolefin porous membrane is severely damaged, so it is necessary to carefully select appropriate light irradiation conditions, taking into account film thickness, etc. preferable. In the case of radiation polymerization, it can be carried out, for example, by using an electron beam irradiation device and irradiating the polymer with an electron beam of about 10 to 50 Mrad at a temperature of 120°C or lower, preferably 100°C or lower. In addition, during these polymerizations, the presence of oxygen in the atmosphere will significantly inhibit the polymerization reaction, so polymerization should be carried out in an inert gas atmosphere such as a nitrogen atmosphere, or in a state where oxygen is substantially absent, such as in a vacuum. is desirable. When a hydrophilic crosslinked polymer is produced using a crosslinkable monomer, the crosslinking reaction may be carried out simultaneously with the polymerization reaction, or the crosslinking may be carried out immediately after the copolymer is produced. Further, the crosslinking reaction by condensation may be carried out using the heat of polymerization reaction, or may be carried out by heating. In particular, when using a crosslinking reaction by condensation, a previously prepared uncrosslinked copolymer of diacetone acrylamide and a crosslinkable monomer is dissolved in a solution and then retained on the pore surface of a polyolefin porous membrane. A method of carrying out a crosslinking reaction in this state may also be used. In this case, the molecular weight of the uncrosslinked copolymer is preferably approximately 10,000 to 500,000, and if the molecular weight is too large, it is difficult to allow the copolymer to penetrate into the pores of the polyolefin porous membrane, which is not preferred. . The molecular weight is more preferably about 50,000 to 300,000. In the present invention, various polymerization methods can be employed as described above, but a method using thermal energy is most preferred. When thermal energy is used, the pores of the porous membrane can be heated to a uniform temperature, so monomers can be uniformly polymerized on all pore surfaces where monomers are held, and the polymerization temperature can be kept low. By setting it appropriately, there is an advantage that polymerization can be carried out without changing the structure of the membrane or deteriorating the membrane substrate. On the other hand, when using light energy, there are problems in that it is difficult for light to reach the pores of a porous membrane due to light scattering, and that increasing the intensity of light irradiation tends to cause deterioration of the membrane substrate. Furthermore, when using radiation energy, there is also the problem that deterioration of the membrane substrate tends to progress. Therefore, when employing these polymerization methods, it is necessary to carefully select polymerization conditions that will not deteriorate the membrane substrate. The monomers held on the pore surface of the polyolefin porous membrane and the above-mentioned uncrosslinked copolymer are polymerized and crosslinked on the porous membrane surface by these polymerization methods, so that the pores of the porous membrane are At least part of the surface is coated with these polymers. After the hydrophilic crosslinked polymer is generated, unnecessary components such as unreacted monomers and free polymers existing around the pore surface of the porous membrane are removed by dipping or press injection using an appropriate solvent. This is desirable.
As the solvent, water, an organic solvent, or a mixed solvent thereof can be used alone or in combination. The hydrophilized porous membrane of the present invention can be produced in this manner, but a particularly preferred method is to add diacetone acrylamide, monomers containing a water-soluble crosslinking monomer, and a polymerization initiator to at least one part of the polyolefin porous membrane. One example is a method in which the polymer is heated and polymerized while it is held on the surface of the pores. When a water-soluble crosslinking monomer is used as a copolymerizable monomer, swelling of the polymer in water is suppressed,
The amount of eluted components can be further reduced, and the hydrophilized porous membrane exhibits excellent water permeability. Furthermore, the hydrophilized porous membrane produced by the heat polymerization method has the characteristics that there is no unevenness in the retention of the polymer in the direction of the membrane thickness, and there is almost no damage to the membrane substrate. Each process has been explained separately above, but
In the present invention, retention of monomers, etc. on the pore surface of the polyolefin porous membrane, solvent removal, polymerization, post-polymerization washing, etc. can be carried out almost continuously. The present invention will be specifically explained below using Examples. In the examples, a polyolefin porous membrane in which slit-shaped spaces (pores) formed by microfibrils and nodules that are obtained by a stretching method are three-dimensionally connected is used. The pore diameter of the porous membrane was expressed by the average width and length of the slit-like spaces. Water permeability, water permeability by alcohol hydrophilization method, and water permeability after polymer retention are determined by the effective membrane area.
The measurement was carried out using a 163 cm 2 test membrane module according to the following method. Further, the retained amount of the polymer, the nodule strength, and the cumulative elution rate were measured by the following method, and the state of coverage of the pore surfaces with the polymer was evaluated by the following method. Furthermore, the solubility of N-hydroxymethylacrylamide, N,N'-methylenebisacrylamide, and triallylisocyanurate used in the examples in water at 30°C is 197 g/dl and 3 g/dl, respectively.
and 0.1 g/dl. (1) Hydraulic pressure: 0.1 Kg/minute from one side of the test membrane module (inside the hollow fiber in the case of hollow fiber membranes)
Supply water at 25°C while increasing the water pressure at a rate of cm2 , and measure the water pressure when the cumulative amount of permeated water reaches 30ml and 50ml. Next, plot the water pressure on the horizontal axis and the amount of permeated water on the vertical axis, find the pressure value at the point where the straight line connecting the two plotted points intersects with the horizontal axis, and use that value as the permeable pressure. (2) Water permeability by alcohol hydrophilization method: Ethanol is pressure-injected for 15 minutes at a flow rate of 25 ml/min from one side of the test membrane module (inside of the hollow fiber membrane in the case of a hollow fiber membrane) that has not been hydrophilized. After thoroughly moistening the inside of the pores of the porous membrane with ethanol, water is flowed at a flow rate of 100 ml/min for 15 minutes to replace the ethanol present inside the pores with water.
Next, water at 25°C was flowed through one side of the test membrane module (inside the hollow fiber in the case of a hollow fiber), the amount of permeated water at a transmembrane pressure difference of 50 mmHg was measured, and from that value the water permeability (/m 2 hr・mmHg). (3) Retained amount of polymer: The nitrogen content is measured by elemental analysis, and it is assumed that this nitrogen comes only from the polymer and that a polymer with the same composition ratio as the monomer composition is formed. Then, the weight percent of the polymer retained with respect to the unit weight of the polyolefin porous membrane is calculated. (4) Evaluation of pore surface coverage: JIS K6768
(1971), the porous membrane was immersed for 1 minute in a standard solution for wetting tests (blue) with a surface tension of 54 dyn/cm, air-dried, and the cross section of the porous membrane was observed using an optical microscope. Examine the distribution state of colored polymers. (5) Knot strength: Measure the knot strength of the porous hollow fiber membrane according to JIS L1013. (6) Cumulative elution rate: The porous membrane has an amount 10 times its weight.
The sample is immersed in warm water at 65°C, and the amount of total organic carbon in the water is measured at regular intervals. Assuming that this total organic carbon content is derived only from the polymer with the composition ratio assumed in (3) above, the cumulative elution amount is calculated, and the cumulative elution rate (weight %). (7) Water permeability after polymer retention: Water at a pressure of 2 Kg/cm 2 is supplied from one side of the test membrane module (inside of the hollow fiber membrane in the case of a hollow fiber membrane) made of a porous membrane retaining the polymer. was injected for 3 hours, water at 25°C was flowed through one side of the test membrane module, the amount of permeated water at a transmembrane pressure difference of 50 mmHg was measured, and the water permeability (/ m2・hr・mmHg) was calculated from that value. demand. Example 1 Slit-like pore width 0.4 μm, length 1.8 μm, porosity 63%, film thickness 70 μm, inner diameter 270 μm, nodule strength 394
A polyethylene porous hollow fiber membrane with a water permeability of 1.1/m 2 ·hr · mmHg by alcohol hydrophilization method and a water permeability of 11 Kg/cm 2 and 100 parts of diacetone acrylamide and 5 parts of N-hydroxymethylacrylamide After being immersed in a treatment solution consisting of 1 part of benzoyl peroxide and 1000 parts of acetone for 10 seconds, it was taken out in nitrogen and air-dried for 5 minutes. Subsequently, this porous membrane was heat-treated at 65°C for 60 minutes in a nitrogen atmosphere, and then water/ethanol = 50/50 (parts)
Unnecessary components were washed away by immersing it in a mixed solvent for 10 minutes and then ultrasonically cleaning it in warm water for 2 minutes.
Next, the solvent was removed by hot air drying to obtain a porous membrane in which the polymer was retained. The water permeability, water permeability, amount of polymer retained, nodule strength, cumulative elution rate, etc. of this porous membrane were measured and the results are shown in Table 1. The water permeability of the hydrophilized porous membrane was good, and the polymer was retained almost uniformly over almost the entire surface of the pores of the porous membrane. In addition, the nodule strength was good, and the mechanical strength did not decrease compared to the original porous membrane. Measurement of the cumulative dissolution rate revealed that there were virtually no eluted components after 24 hours. Examples 2 to 4 N-hydroxymethylacrylamide was used as the crosslinking monomer in the amount shown in Table 1, and the other conditions were the same as in Example 1 to retain the polymer in the porous membrane. The performance of the hydrophilized porous membrane thus obtained was evaluated, and the results shown in Table 1 were obtained. Example 5 As a porous membrane, the width of the slit-like pores is 0.2 μm, the length is 0.7 μm, the porosity is 45%, the membrane thickness is 22 μm, the inner diameter is 200 μm,
A polypropylene porous hollow fiber membrane with a water permeability of 12 Kg/cm 2 and a water permeability of 0.54/m 2 ·hr · mmHg by alcohol hydrophilization method was treated with 100 parts of diacetone acrylamide and N,N'-methylene bis as a treatment solution. The polymer was prepared in the same manner as in Example 1, except that a solution consisting of 5 parts of acrylamide, 5 parts of 2,2'-azobisisobutyronitrile, and 800 parts of acetone was used, and the heat treatment conditions were 65°C for 60 minutes. A retained porous membrane was obtained and its performance was evaluated and shown in Table 1. The polymer was retained almost uniformly over almost the entire surface of the pores. It was found that there were virtually no eluted components after 24 hours. Examples 6 to 8 N,N'-methylenebisacrylamide was used as the crosslinking monomer in the amount shown in Table 1, and the other conditions were the same as in Example 5 to retain the polymer in the porous membrane. . The performance of the hydrophilized porous membrane thus obtained was evaluated, and the results shown in Table 1 were obtained. Example 9 As a porous membrane, the width of slit-like pores is 0.8 μm, the length is 3.0 μm, the porosity is 70%, the membrane thickness is 42 μm, and the permeability pressure is 4.5.
Kg/cm 2 , water permeability by alcohol hydrophilization method
A polyethylene porous flat membrane of 3.5/ m2・hr・mmHg was treated with diacetone acrylamide as a treatment solution.
100 parts, N-hydroxymethylacrylamide 5
A porous membrane retaining a polymer was obtained in the same manner as in Example 1 except that a solution consisting of 10 parts of benzoyl peroxide and 330 parts of methyl ethyl ketone was used, and the heat treatment conditions were 60°C for 60 minutes. Performance was evaluated and the results shown in Table 1 were obtained. The polymer was retained almost uniformly over almost the entire surface of the pores. It was found that there were virtually no eluted components after 24 hours. Examples 10 to 12 N-hydroxymethylacrylamide was used as the crosslinking monomer in the amount shown in Table 1, and the other conditions were the same as in Example 9 to retain the polymer in the porous membrane. The performance of the hydrophilized porous membrane thus obtained was evaluated, and the results shown in Table 1 were obtained. Example 13 5 parts of triallylisocyanurate was used as a crosslinking monomer, and the other conditions were the same as in Example 1 to retain a polymer in a porous membrane. The performance of the hydrophilized porous membrane thus obtained was evaluated, and the results shown in Table 2 were obtained. The polymer was held almost uniformly over almost the entire surface of the pores. Example 14 5 parts of triallylisocyanurate was used as a crosslinking monomer, and the other conditions were the same as in Example 5 to retain a polymer in a porous membrane. The performance of the porous membrane thus obtained was evaluated, and the results shown in Table 2 were obtained. Example 15 100 parts of diacetone acrylamide, 1 part of divinylbenzene, 0.3 parts of benzoyl peroxide,
A solution consisting of 450 parts of methyl ethyl ketone was used, the immersion time was 3 seconds, and the thermal polymerization conditions were 70° C. for 60 minutes, and the other conditions were exactly the same as in Example 5 to retain the polymer in the porous membrane. The performance of this porous membrane was evaluated and the results shown in Table 2 were obtained. The polymer was held almost uniformly over almost the entire surface of the pores of the porous membrane. Measurement of the cumulative dissolution rate revealed that there were virtually no eluted components after 24 hours. Example 16 Using the same polyethylene porous flat membrane as in Example 9, and using a solution consisting of 100 parts of diacetone acrylamide, 5 parts of triallylisocyanurate, 5 parts of benzoyl peroxide, and 330 parts of acetone, the immersion time was A hydrophilized porous membrane of the present invention was obtained in the same manner as in Example 9 except that the heat treatment conditions were 60° C. for 30 minutes. The performance was also evaluated and the results shown in Table 2 were obtained. Example 17 Poly-4 whose slit-like pores have a width of 0.2 μm, a length of 0.5 μm, a porosity of 43%, a film thickness of 35 μm, and a water permeability determined by alcohol hydrophilization method of 0.2/m 2 ·hr · mmHg.
- Same as Example 1 except that a porous flat membrane of methyl-1-pentene was used, the amount of benzoyl peroxide was 0.5 parts, the immersion time in the solution was 3 seconds, and the heating polymerization conditions were 75°C for 25 minutes. A hydrophilized porous membrane of the present invention was obtained, and its performance was evaluated, and the results shown in Table 2 were obtained. The polymer was held almost uniformly over almost the entire surface of the pores of the porous membrane. Examples 18-21 Polyethylene porous hollow fiber membranes similar to those in Example 1 were continuously supplied at a speed of 2 m/min and immersed in a 10 cm long solution bath to form a pipe 1 with a diameter of 2 cm and a length of 4 m. The adhering liquid was removed and dried in the tube, and then the monomers were polymerized by heating in a pipe 2 having a diameter of 2 cm and a length of 3 m. The composition of each solution was 100 parts of diacetone acrylamide, N-hydroxymethyl acrylamide in the amounts shown in Table 2, and bis-(4-tert-butylcyclohexyl) peroxydicarbonate.
0.5 parts and 660 parts of acetone. Nitrogen at room temperature was flowed into pipe 1, and heated nitrogen at 80°C was flowed into pipe 2 at a rate of 3/min. Next, this hollow fiber membrane was mixed with water/ethanol = 50/50.
A 50cm long tank containing (part) of mixed solvent and 60℃
The hydrophilized porous membrane of the present invention was obtained by passing through a 1.5 m long water tank overflowing hot water for washing, and further drying in a hot air atmosphere. The performance of the porous membrane was evaluated and the results shown in Table 2 were obtained. The polymer was held almost uniformly over almost the entire surface of the pores of these porous membranes.
【表】【table】
【表】【table】
本発明の方法によれば、ポリオレフイン多孔質
膜基質の機械的強度を低下させることなく、親水
性の重合体をポリオレフイン多孔質膜内部の細孔
表面上にもほぼ均一に強固に保持させることが可
能である。
本発明の親水化多孔質膜は重合体が保持されて
いないポリオレフイン多孔質膜と比較すると透水
圧が著しく低く、透水性能が極めて優れており、
この重合体はポリオレフイン多孔質膜の細孔表面
に強固に保持されているので、温水中における溶
出試験においても溶出成分の量が極めて少ない。
従つて、本発明の親水化多孔質膜は高温処理をは
じめとする水処理分野や血液浄化分野等において
使用することができる。
特に、延伸法によつて多孔質化されたポリオレ
フインから得られる親水化多孔質膜は良好な親水
性を示すと共に使用時における目詰まりによる
過抵抗の増加が少ないという利点を有している。
According to the method of the present invention, it is possible to firmly hold a hydrophilic polymer almost uniformly on the pore surface inside the porous polyolefin membrane without reducing the mechanical strength of the porous polyolefin membrane substrate. It is possible. The hydrophilized porous membrane of the present invention has a significantly lower water permeability pressure than a polyolefin porous membrane in which no polymer is retained, and has extremely excellent water permeability.
Since this polymer is firmly held on the pore surface of the polyolefin porous membrane, the amount of eluted components is extremely small even in an elution test in hot water.
Therefore, the hydrophilized porous membrane of the present invention can be used in the water treatment field including high temperature treatment, the blood purification field, and the like. In particular, a hydrophilized porous membrane obtained from a polyolefin made porous by a stretching method has the advantage that it exhibits good hydrophilicity and that there is little increase in excessive resistance due to clogging during use.
Claims (1)
を含むモノマー類からなる親水性架橋重合体をポ
リオレフイン多孔質膜の少なくとも一部の細孔表
面に保持させてなる親水化多孔質膜。 ２ ジアセトンアクリルアミドと架橋性モノマー
を含むモノマー類からなる親水性架橋重合体をポ
リオレフイン多孔質膜の少なくとも一部の細孔表
面に物理的に保持させてなる特許請求の範囲第１
項記載の多孔質膜。 ３ ポリオレフイン多孔質膜が延伸法によつて多
孔質化されたものである特許請求の範囲第１項又
は第２項記載の多孔質膜。 ４ ポリオレフイン多孔質膜が中空糸の形状を有
するものである特許請求の範囲第１項又は第２項
記載の多孔質膜。 ５ ポリオレフインがエチレン、プロピレン、４
−メチル−１−ペンテンおよび３−メチル−１−
ブテンからなる群より選ばれる一種以上のモノマ
ーを主成分とする重合体である特許請求の範囲第
１項又は第２項記載の多孔質膜。 ６ 架橋性モノマーが水溶性の架橋性モノマーの
ある特許請求の範囲第１項又は第２項記載の多孔
質膜。 ７ ジアセトンアクリルアミドと架橋性モノマー
を含むモノマー類をポリオレフイン多孔質膜の少
なくとも一部の細孔表面上に保持させた状態で加
熱重合させることを特徴とする親水化多孔質膜の
製造方法。 ８ 水および／または有機溶剤からなる溶媒にモ
ノマー類を溶解した溶液を調製し、ポリオレフイ
ン多孔質膜に該溶液を含浸させた後、該溶媒を揮
発除去することにより該モノマー類を該多孔質膜
の表面上に保持させる特許請求の範囲第７項記載
の方法。 ９ ポリオレフイン多孔質膜が延伸法によつて多
孔質化されたものである特許請求の範囲第７項記
載の方法。 １０ ポリオレフイン多孔質膜が中空糸の形状を
有するものである特許請求の範囲第７項記載の方
法。 １１ ポリオレフインがエチレン、プロピレン、
４−メチル−１−ペンテンおよび３−メチル−１
−ブテンからなる群より選ばれる一種以上のモノ
マーを主成分とする重合体である特許請求の範囲
第７項記載の方法。 １２ 架橋性モノマーの30℃の水における溶解度
が１ｇ／dl以上である特許請求の範囲第７項記載
の方法。[Scope of Claims] 1. A hydrophilic porous membrane comprising a hydrophilic crosslinked polymer made of monomers containing diacetone acrylamide and a crosslinkable monomer, held on the surface of at least some pores of a polyolefin porous membrane. 2. Claim 1, wherein a hydrophilic crosslinked polymer made of monomers including diacetone acrylamide and a crosslinkable monomer is physically retained on the surface of at least some pores of a porous polyolefin membrane.
The porous membrane described in Section 1. 3. The porous membrane according to claim 1 or 2, wherein the polyolefin porous membrane is made porous by a stretching method. 4. The porous membrane according to claim 1 or 2, wherein the polyolefin porous membrane has a hollow fiber shape. 5 Polyolefin is ethylene, propylene, 4
-Methyl-1-pentene and 3-methyl-1-
The porous membrane according to claim 1 or 2, which is a polymer whose main component is one or more monomers selected from the group consisting of butene. 6. The porous membrane according to claim 1 or 2, wherein the crosslinking monomer is a water-soluble crosslinking monomer. 7. A method for producing a hydrophilized porous membrane, which comprises heating and polymerizing monomers containing diacetone acrylamide and a crosslinking monomer while retaining them on at least some pore surfaces of a polyolefin porous membrane. 8 Prepare a solution of monomers dissolved in a solvent consisting of water and/or an organic solvent, impregnate a polyolefin porous membrane with the solution, and then remove the monomers by evaporating the solvent. 8. The method according to claim 7, wherein the method is carried out on the surface of a . 9. The method according to claim 7, wherein the polyolefin porous membrane is made porous by a stretching method. 10. The method according to claim 7, wherein the polyolefin porous membrane has a hollow fiber shape. 11 Polyolefin is ethylene, propylene,
4-methyl-1-pentene and 3-methyl-1
- The method according to claim 7, wherein the polymer is a polymer whose main component is one or more monomers selected from the group consisting of butene. 12. The method according to claim 7, wherein the crosslinking monomer has a solubility in water at 30°C of 1 g/dl or more.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61-951 | 1986-01-07 | ||
| JP61000951 | 1986-01-07 | ||
| JP61-221465 | 1986-09-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63190602A JPS63190602A (en) | 1988-08-08 |
| JPH0317531B2 true JPH0317531B2 (en) | 1991-03-08 |
Family
ID=11487980
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62000319A Granted JPS63190602A (en) | 1986-01-07 | 1987-01-05 | Hydrophilic porous membrane and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63190602A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH082994B2 (en) * | 1987-03-12 | 1996-01-17 | 日本原子力研究所 | Method for producing modified open-cell polyolefin foam |
| EP0342239B1 (en) * | 1987-11-04 | 1993-02-24 | Mitsubishi Rayon Co., Ltd | Porous membrane and process for its production |
| WO1992009359A1 (en) * | 1990-11-28 | 1992-06-11 | Mitsubishi Rayon Co., Ltd. | Large-pore-diameter porous hollow yarn membrane of polyethylene, production thereof, and hydrophilic porous hollow yarn membrane of polyethylene |
| WO2001051170A1 (en) * | 2000-01-14 | 2001-07-19 | Mykrolis Corporation | System and method for liquid filtration based on a neutral filter material |
| EP1381447B1 (en) * | 2001-04-27 | 2007-01-24 | Millipore Corporation | Coated membranes |
| US7073671B2 (en) * | 2002-06-07 | 2006-07-11 | Millipore Corporation | Microporous membrane substrate having caustic stable, low protein binding surface |
| JP2007519522A (en) * | 2004-01-27 | 2007-07-19 | インテグリス・インコーポレーテッド | A method for removing fine bubbles from a liquid. |
| US7553417B2 (en) * | 2005-12-30 | 2009-06-30 | 3M Innovative Properties Company | Functionalized substrates |
| US10092881B2 (en) | 2008-01-25 | 2018-10-09 | Bha Altair, Llc | Permanent hydrophilic porous coatings and methods of making them |
| US8132676B2 (en) * | 2008-08-18 | 2012-03-13 | Emd Millipore Corporation | Hydrophilic, high protein binding, low fluorescence, western blotting membrane |
-
1987
- 1987-01-05 JP JP62000319A patent/JPS63190602A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63190602A (en) | 1988-08-08 |
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