JPS6123875B2 - - Google Patents
Info
- Publication number
- JPS6123875B2 JPS6123875B2 JP55116404A JP11640480A JPS6123875B2 JP S6123875 B2 JPS6123875 B2 JP S6123875B2 JP 55116404 A JP55116404 A JP 55116404A JP 11640480 A JP11640480 A JP 11640480A JP S6123875 B2 JPS6123875 B2 JP S6123875B2
- Authority
- JP
- Japan
- Prior art keywords
- exchange membrane
- ion exchange
- electrode
- wire
- porous layer
- 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
Links
- 239000003014 ion exchange membrane Substances 0.000 claims description 35
- 239000002184 metal Substances 0.000 claims description 20
- 229910052751 metal Inorganic materials 0.000 claims description 19
- 230000000694 effects Effects 0.000 claims description 11
- 150000002739 metals Chemical class 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 5
- 238000010030 laminating Methods 0.000 claims description 3
- 238000005868 electrolysis reaction Methods 0.000 description 17
- 239000012528 membrane Substances 0.000 description 16
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 239000003513 alkali Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 14
- -1 hydroxide ions Chemical class 0.000 description 12
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 11
- 239000007789 gas Substances 0.000 description 11
- 238000005342 ion exchange Methods 0.000 description 11
- 229920000642 polymer Polymers 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 239000000178 monomer Substances 0.000 description 10
- 230000000704 physical effect Effects 0.000 description 10
- 239000000243 solution Substances 0.000 description 10
- 238000005341 cation exchange Methods 0.000 description 9
- 239000003518 caustics Substances 0.000 description 8
- 229910052731 fluorine Inorganic materials 0.000 description 8
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 7
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 7
- 239000011737 fluorine Substances 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 6
- 229920001577 copolymer Polymers 0.000 description 6
- 125000000524 functional group Chemical group 0.000 description 6
- 229910052719 titanium Inorganic materials 0.000 description 6
- 239000010936 titanium Substances 0.000 description 6
- 229910052739 hydrogen Inorganic materials 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 5
- 239000011148 porous material Substances 0.000 description 5
- 235000011121 sodium hydroxide Nutrition 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- 125000002843 carboxylic acid group Chemical group 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 4
- 239000004810 polytetrafluoroethylene Substances 0.000 description 4
- 125000000542 sulfonic acid group Chemical group 0.000 description 4
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 229910052801 chlorine Inorganic materials 0.000 description 3
- 238000006116 polymerization reaction Methods 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M sodium chloride Inorganic materials [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 3
- 125000000008 (C1-C10) alkyl group Chemical group 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical group C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- 229910001413 alkali metal ion Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910052732 germanium Inorganic materials 0.000 description 2
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- MIZLGWKEZAPEFJ-UHFFFAOYSA-N 1,1,2-trifluoroethene Chemical group FC=C(F)F MIZLGWKEZAPEFJ-UHFFFAOYSA-N 0.000 description 1
- CHRJZRDFSQHIFI-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;styrene Chemical compound C=CC1=CC=CC=C1.C=CC1=CC=CC=C1C=C CHRJZRDFSQHIFI-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 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
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical group OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- OKDDRJHDLHFWGT-UHFFFAOYSA-N [Ir+]=O.[O-2].[Ti+4].[Ru+]=O.[O-2].[O-2] Chemical compound [Ir+]=O.[O-2].[Ti+4].[Ru+]=O.[O-2].[O-2] OKDDRJHDLHFWGT-UHFFFAOYSA-N 0.000 description 1
- PFYPSSPANKKGGA-UHFFFAOYSA-N [O-2].[Ti+4].[Ir+]=O Chemical compound [O-2].[Ti+4].[Ir+]=O PFYPSSPANKKGGA-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical group 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- UUAGAQFQZIEFAH-UHFFFAOYSA-N chlorotrifluoroethylene Chemical group FC(F)=C(F)Cl UUAGAQFQZIEFAH-UHFFFAOYSA-N 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000003411 electrode reaction Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- 150000002431 hydrogen Chemical group 0.000 description 1
- 229910000039 hydrogen halide Inorganic materials 0.000 description 1
- 239000012433 hydrogen halide Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 1
- 239000013618 particulate matter Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- ABLZXFCXXLZCGV-UHFFFAOYSA-N phosphonic acid group Chemical group P(O)(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 125000001453 quaternary ammonium group Chemical group 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 1
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 229910001936 tantalum oxide Inorganic materials 0.000 description 1
- 238000012719 thermal polymerization Methods 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
Landscapes
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Description
本発明はイオン交換膜電解槽、特に低電圧で塩
化アルカリ水溶液を電解して苛性アルカリを得る
際用いられるイオン交換膜電解槽に係るものであ
る。
塩化アルカリ水溶液を隔膜法により電解して苛
性アルカリを得る方法は、隔膜としてアスベスト
を用いる方法に代つて、より高純度、高濃度の苛
性アルカリを得る目的でイオン交換膜を用いる方
法が提案されている。他方、近年省エネルギーが
世界的に進行しつつなり、この観点からこの種技
術においては電解電圧を極力低くすることが望ま
れる。電解電圧の低下手段としては、従来陽極や
陰極の材質、又は組成、形状を考慮したり、或い
は用いるイオン交換膜の組成やイオン交換基の種
類を特定化する等種々の手段が提案されている。
これらの方法においては、何れもそれなりの効
果はあるものの、大多数のものは得られる苛性ア
ルカリの濃度がそれ程高くない処に上限を有し、
これを超えると急激に電解電圧の上昇や、電流効
率の低下を来たし、或いは電解電圧低下現象の持
続性、耐久性等が劣る等必ずしも工業的に十分満
足し得るものばかりではなかつた。
又、含弗素陽イオン交換膜の表面にガス及び液
透過性の陽極や陰極を結合てしめた電解槽にて塩
化アルカリ水溶液を電解して苛性アルカリを製造
する方法が提案されている。(特開昭54−112398
号公報参照)
この方法は、従来この種技術においては避け難
いと考えられていた被電解液による電気抵抗や、
発生する水素や塩素ガスに基づく泡による電気抵
抗を極力減らせる為、従来より一層低電圧で電解
を実施し得る手段として有望である。
この方法における陽極や陰極は、イオン交換膜
表面に結合し、埋め込むように設けられ、そし
て、膜と電極との接触界面で電解により発生した
ガスは電極から容易に離脱し、且電解液が浸透し
得るようにガス及び液透過性にされている。
この様な多孔質の電極は、通常陽極や陰極とし
ての活性粒子と、これを結合する物質、更に好ま
しくは黒鉛その他の導電材料が均一に混合され、
薄層状に成形された多孔質体から成つている。
しかしながら、本発明者の検討によると、この
様な電極を直接イオン交換膜に結合せしめた電解
槽を用いる場合には、電解槽における例えば陽極
は、陰極室から逆拡散する水酸イオンと接触する
為、従来の耐塩素性の他に、耐アルカリ性も要求
され、必然的に特殊、高価な材質が要求される
他、電極とイオン交換膜とが直接結合されている
為、電極反応によつて発生したガスにより、イオ
ン交換膜に部分的な膨れが生じる等膜性能が劣化
する等長期にわたり安定した操業が困難となる虞
れがあることが判明した。
本発明者は、かかる欠点を除去し、可及的に低
い槽電圧で苛性アルカリを得る手段を見出すこと
を目的として種々研究、検討した結果、陽イオン
交換膜の表面に電極活性を有しないガス及び液透
過性の多孔質層を形成し、これが介して陽極又は
陰極を配置せしめた電解槽を用いることにより、
前記目的を達成し得ることを見出し、既に特願昭
55−13012号として提案した。
この電解槽においても、好ましくは電解体は陽
イオン交換膜に接触して、或はその近傍に配置せ
しめられるが、かゝる場合、電解により発生する
水素や塩素ガスをいかに円滑且つ十分に電極体か
ら離脱させ得るか、更には電解時におけるイオン
交換膜の変形を槽電圧の上昇なく防止できうるか
が要求される。
本発明者は、かゝる点に鑑み、ガスの離脱が良
好で、且つイオン交換膜の変形を槽電圧の上昇な
く防止できる電解槽を得ることを目的として種々
研究した結果、イオン交換膜面に近い程目が細か
く、線径も細く、電極面から離れるに従つて目が
粗く、線径の太い必要に応じて被覆を施こしたエ
キスパンデツドメタル又は金網を複数枚を積層し
てなる電極体を配置することにより前記目的を達
成し得ることを見い出した。
かくして本発明は、イオン交換膜面に形成され
た電極活性を有しないガス及び液透過性の多孔質
層に対し、電極体を接触させるか又はその近傍に
配置せしめた電極槽であつて、上記電極体が、目
が細かく線径の細いエキスパンデツドメタル又は
金網から、順次目が粗く線径の太いエキスパンデ
ツドメタル又は金網を複数枚積層して構成された
ことを特徴とするイオン交換膜電解槽にある。
本発明において、イオン交換膜面に直接接触す
る電極体材料にエキスパンデツドメタルを採用す
る場合には、その物性としては孔の長径が1.0〜
20mm、短径が0.5〜10mm、線径0.1〜1.5mm、開孔率
30〜90%程度を有するのが適当である。これら物
性が前記範囲を逸脱する場合には槽電圧が上昇し
たり、イオン膜が大きくたわんで好ましくない。
そしてこれら物性のうち、孔の長径が0.1〜10
mm、短径が0.5〜5mm、線径0.2〜1.3mm、開孔率35
〜85%を採用する場合には良好なガスの離脱効果
を期待し得ると共に、槽電圧の上昇も実質的にな
く安定した電解操業が出来るので特に好ましい。
又、同じく電極体材料に金網が用いられる場合
には、その物性として5〜160メツシユ、線径0.1
〜2mm程度を採用するのが適当である。そしてこ
れらのうち6〜100メツシユ、線径0.15〜1.8mmを
採用する場合には、良好なガスの離脱効果を期待
し得ると共に、槽電圧の上昇も実質的になく、安
定した電解操業を実施し得るので特に好ましい。
又、最もイオン交換膜面から離れた、いわば最
外部に来る電極体材料の物性としては、これをエ
キスパンデツドメタルで構成する場合には孔の長
径が6〜150mm、短径が3〜60mm、線径0.4〜11
mm、開孔率30〜93%を採用するのが適当である。
これら物性が前記範囲を逸脱する場合には、ガス
抜けが悪くなつたり、細かいメツシユを充分に保
持できなくなる。そしてこれらのうち、孔の長径
が7〜140mm、短径が4〜50mm、線径0.6〜10mm、
開孔率40〜90%を採用する場合には、十分なガス
抜け効果を期待しうると共に、十分な保持効果も
期待し得るので特に好ましい。又、金網が用いら
れる場合には、その物性として4〜100メツシ
ユ、線径0.1〜3mm程度を採用するのが適当であ
る。特には5〜80メツシユ、線径0.2〜2mmを採
用するのが特に好ましい。
これらエキスパンデツドメタルや金網は、適宜
組み合わせて用いることができ、更に中間に位置
するエキスパンデツドメタルや金網は、前記の如
き小さい物性を有するものから、大きい物性を有
するものの間で適宜選ばれる。
これら電極体を積層するにあたつては、これを
例えば、適当な枠を用いてこれに積層物を予め嵌
め込み固定せしめておいたものを用いることもで
き、或は使用時に、その都度イオン交換膜面に対
し、目の細いものから目の粗いものへと順次配置
して、これを後述するような手段により、使用時
或は電解槽の組み立て時に一体化せしめることも
できる。
これら電極体を構成するエキスパンデツドメタ
ル又は金網材質としては、例えば陰極側にはステ
ンレス、ニツケル、鉄が使用され、陽極側にはチ
タン、タンタル、ニオブ、ジルコニウム等に白金
族金属及びその合金、白金族金属酸化物及びその
混合物を被覆したものが使用され得る。
本発明においてイオン交換膜に結合して用いら
れる多孔質層は、陽極側或は陰極側の少なくとも
一方である。そしてこの様な多孔質層は、液及び
ガス透過性の薄層であり、その物性は陰、陽極の
何れであつても平均細孔径0.01〜200μ、多孔率
10〜99%、厚み0.01〜100μ、好ましくは平均細
孔径0.1〜100μ、多孔率20〜95%、厚み0.1〜50
μを有するのが適当である。
そしてかゝる多孔質層を得る場合には、例えば
多孔質層形成物質の粉末乃至粒状物を必要に応じ
てポリテトラフルオロエチレン等の含弗素重合体
から成る結合剤を用い、薄層状に形成する。多孔
質層形成物質としては、使用条件において、耐食
性を有するものならば一応使用しうるが、なかで
も周期律表−A族(好ましくはゲルマニウム、
スズ、鉛)、−B族(好ましくは、チタン、ジ
ルコニウム、ハフニウム)、−B族(好ましく
は、ニオブ、タンタル)、鉄族金属(鉄、コバル
ト、ニツケル)クロム、マンガンなどの単体又は
合金、或いはその酸化物、水酸化物、窒化物又は
炭化物が使用される。
かくして、イオン交換膜面に形成される電極活
性を有しない多孔質層は、多孔層中に電極活性を
有しない粒状物が、好ましくは、0.01〜100mg/
cm2、特に0.1〜10mg/cm2含有するようにさせるの
が適切である。
本発明の電解槽において、電極体を使用する具
体的手段としては、好ましくは多孔質層に対し、
電極体を接触させ、例えば1Kg/cm2までの圧力に
て軽く押しつけるようにして用いられる。接触さ
せ、押しつける手段としては、例えば適当な枠体
を用い、これでバネ或は螺子により締めつけるよ
うにする手段や、イオン交換膜面の反対側の膜面
(極室)側から、その極室液圧によつて電極上多
孔質層を押しつける等、その他適宜な手段を採用
し得る。
しかしながら、本発明の電解槽で電極体は、必
ずしも多孔質層と接触して配置する必要はなく、
場合により例えば0.1〜5mmの間隔をもつて配置
しても良い。
本発明に用いられるイオン交換膜としては、例
えばカルボキシル基、スルホン酸基、ホスホン酸
基、フエノール性水酸基等の陽イオン交換基を含
有する重合体から成り、かゝる重合体としては含
弗素重合体を採用するのが特に好ましい。
イオン交換基含有の含弗素重合体としては、例
えばテトラフルオロエチレン、クロロトリフルオ
ロエチレン等のビニルモノマーとスルホン酸、カ
ルボン酸、燐酸基等のイオン交換基、或はイオン
交換基に転換し得る反応性基を有するパーフルオ
ロのビニルモノマーとの共重合体が好ましい。
又、トリフルオロエチレンの膜状重合体にスルホ
ン酸基等のイオン交換基を導入したものや、スチ
レンジビニルベンゼンにスルホン酸基を導入した
もの等も使用できる。そしてこれらのうち、夫々
以下の(イ)、(ロ)の構造を有する重合体の使用が好ま
しい。
(イ) (−CF2−CXX′)−
The present invention relates to an ion exchange membrane electrolytic cell, particularly an ion exchange membrane electrolytic cell used when electrolyzing an aqueous alkali chloride solution to obtain caustic alkali at low voltage. As a method for obtaining caustic alkali by electrolyzing an aqueous alkali chloride solution using a diaphragm method, a method using an ion exchange membrane has been proposed to replace the method of using asbestos as a diaphragm for the purpose of obtaining a higher purity and higher concentration of caustic alkali. There is. On the other hand, in recent years, energy conservation has been progressing worldwide, and from this point of view, it is desired to reduce the electrolysis voltage as much as possible in this type of technology. Various methods have been proposed to lower the electrolytic voltage, such as considering the material, composition, and shape of the anode and cathode, or specifying the composition of the ion exchange membrane used and the type of ion exchange group. . Although all of these methods have certain effects, most of them have an upper limit where the concentration of the caustic alkali obtained is not so high.
If this value is exceeded, the electrolytic voltage suddenly increases, the current efficiency decreases, or the sustainability and durability of the electrolytic voltage drop phenomenon deteriorates, so that the electrolytic voltage is not always fully satisfactory industrially. Furthermore, a method has been proposed for producing caustic alkali by electrolyzing an aqueous alkali chloride solution in an electrolytic cell in which a gas- and liquid-permeable anode and a cathode are bonded to the surface of a fluorine-containing cation exchange membrane. (Unexamined Japanese Patent Publication No. 54-112398
(Refer to the publication) This method reduces the electrical resistance caused by the electrolyte, which was previously thought to be unavoidable in this type of technology,
This method is promising as a means to perform electrolysis at a lower voltage than conventional methods because it can minimize the electrical resistance caused by bubbles generated from hydrogen and chlorine gas. In this method, the anode and cathode are bonded to and embedded in the surface of the ion exchange membrane, and the gas generated by electrolysis at the contact interface between the membrane and electrode easily leaves the electrode, and the electrolyte permeates. It is made permeable to gases and liquids so that it can be used. Such porous electrodes usually consist of a uniform mixture of active particles as an anode or a cathode, and a substance that binds them, preferably graphite or other conductive material.
It consists of a porous body formed into a thin layer. However, according to studies conducted by the present inventors, when using an electrolytic cell in which such an electrode is directly bonded to an ion exchange membrane, for example, the anode in the electrolytic cell comes into contact with hydroxide ions that diffuse back from the cathode chamber. Therefore, in addition to the conventional chlorine resistance, alkali resistance is also required, which necessarily requires special and expensive materials.In addition, since the electrode and ion exchange membrane are directly connected, the electrode reaction It has been found that the generated gas may cause partial bulges in the ion exchange membrane, deteriorating membrane performance, and making stable operation difficult over a long period of time. As a result of various studies and examinations aimed at eliminating such drawbacks and finding a means to obtain caustic alkali with as low a cell voltage as possible, the present inventor discovered that a gas having no electrode activity on the surface of a cation exchange membrane. By using an electrolytic cell in which a liquid-permeable porous layer is formed and an anode or a cathode is disposed through the porous layer,
It was discovered that the above purpose could be achieved, and a patent application has already been filed.
It was proposed as No. 55-13012. In this electrolytic cell, the electrolyte is preferably placed in contact with or near the cation exchange membrane, but in such a case, how can hydrogen and chlorine gas generated by electrolysis be transferred smoothly and sufficiently to the electrodes? It is required to be able to remove the ion exchange membrane from the body, and to prevent deformation of the ion exchange membrane during electrolysis without increasing cell voltage. In view of the above, the present inventor conducted various studies with the aim of obtaining an electrolytic cell that allows good gas release and prevents deformation of the ion exchange membrane without increasing cell voltage. The closer the wire is to the electrode surface, the finer the mesh and the thinner the wire diameter, and the farther away from the electrode surface, the coarser the wire diameter.Made by laminating multiple sheets of expanded metal or wire mesh coated as necessary. It has been found that the above object can be achieved by arranging the electrode body. Thus, the present invention provides an electrode vessel in which an electrode body is placed in contact with or in the vicinity of a gas and liquid permeable porous layer that has no electrode activity and is formed on the surface of an ion exchange membrane. An ion exchange membrane characterized in that the electrode body is constructed by laminating a plurality of expanded metals or wire meshes with coarse meshes and large wire diameters in sequence from expanded metals or wire meshes with fine meshes and thin wire diameters. It's in the electrolytic tank. In the present invention, when expanded metal is used as the electrode material that comes into direct contact with the ion exchange membrane surface, the physical properties of the expanded metal are such that the long diameter of the pores is 1.0 to 1.
20mm, short diameter 0.5~10mm, wire diameter 0.1~1.5mm, open area ratio
It is appropriate to have about 30 to 90%. If these physical properties deviate from the above ranges, the cell voltage will increase or the ion membrane will be greatly warped, which is undesirable.
Among these physical properties, the long diameter of the pores is 0.1 to 10
mm, short axis 0.5 to 5 mm, wire diameter 0.2 to 1.3 mm, open area ratio 35
It is particularly preferable to use a ratio of 85% to 85%, since a good gas desorption effect can be expected and stable electrolytic operation can be performed with virtually no increase in cell voltage. Similarly, when wire mesh is used as the electrode body material, its physical properties are 5 to 160 mesh, wire diameter 0.1
It is appropriate to adopt a thickness of about 2 mm. If 6 to 100 meshes and wire diameters of 0.15 to 1.8 mm are used, a good gas release effect can be expected, and there will be virtually no increase in cell voltage, resulting in stable electrolysis operation. This is particularly preferable because it can be done. In addition, the physical properties of the electrode body material located furthest away from the ion exchange membrane surface, so to speak, are such that when it is made of expanded metal, the long diameter of the pores is 6 to 150 mm, and the short diameter is 3 to 60 mm. , wire diameter 0.4~11
It is appropriate to adopt a hole area ratio of 30 to 93%.
If these physical properties deviate from the above ranges, gas release may be impaired or fine mesh may not be retained sufficiently. Among these, the long axis of the hole is 7 to 140 mm, the short axis is 4 to 50 mm, the wire diameter is 0.6 to 10 mm,
It is particularly preferable to use a porosity of 40 to 90%, since a sufficient gas release effect and a sufficient retention effect can also be expected. Further, when a wire mesh is used, it is appropriate to use a wire mesh having physical properties of 4 to 100 mesh and a wire diameter of about 0.1 to 3 mm. In particular, it is particularly preferable to use 5 to 80 meshes and a wire diameter of 0.2 to 2 mm. These expanded metals and wire meshes can be used in appropriate combinations, and the expanded metals and wire meshes located in the middle are selected as appropriate from those with small physical properties to those with large physical properties as described above. . When stacking these electrode bodies, it is possible to use, for example, a structure in which the laminate is fitted and fixed in advance using a suitable frame, or ion exchange is performed each time during use. It is also possible to arrange them sequentially from narrow to coarse on the membrane surface and integrate them during use or when assembling the electrolytic cell by means described later. The expanded metal or wire mesh material constituting these electrode bodies includes, for example, stainless steel, nickel, or iron for the cathode side, and titanium, tantalum, niobium, zirconium, platinum group metals, and alloys thereof, and the like for the anode side. Coatings of platinum group metal oxides and mixtures thereof may be used. In the present invention, the porous layer used in conjunction with the ion exchange membrane is at least one of the anode side and the cathode side. Such a porous layer is a thin layer that is permeable to liquid and gas, and its physical properties include an average pore diameter of 0.01 to 200μ and a porosity of
10-99%, thickness 0.01-100μ, preferably average pore diameter 0.1-100μ, porosity 20-95%, thickness 0.1-50
It is appropriate to have μ. In order to obtain such a porous layer, for example, powder or granules of a porous layer-forming material are formed into a thin layer using a binder made of a fluorine-containing polymer such as polytetrafluoroethylene, if necessary. do. As the porous layer-forming material, any material can be used as long as it has corrosion resistance under the conditions of use, but in particular, materials from Group A of the periodic table (preferably germanium, germanium,
-B group (preferably titanium, zirconium, hafnium), -B group (preferably niobium, tantalum), iron group metals (iron, cobalt, nickel), chromium, manganese, etc. Alternatively, its oxide, hydroxide, nitride or carbide may be used. In this way, the porous layer having no electrode activity formed on the surface of the ion-exchange membrane preferably contains 0.01 to 100 mg of particulate matter having no electrode activity in the porous layer.
cm 2 , particularly 0.1 to 10 mg/cm 2 . In the electrolytic cell of the present invention, as a specific means for using the electrode body, preferably, for the porous layer,
It is used by bringing the electrode body into contact and pressing lightly, for example, at a pressure of up to 1 kg/cm 2 . Examples of means for contacting and pressing include using a suitable frame and tightening it with springs or screws, or pressing the electrode chamber from the opposite membrane surface (electrode chamber) side of the ion exchange membrane surface. Other appropriate means, such as pressing the porous layer on the electrode with liquid pressure, may be employed. However, in the electrolytic cell of the present invention, the electrode body does not necessarily need to be placed in contact with the porous layer;
Depending on the case, they may be arranged at intervals of, for example, 0.1 to 5 mm. The ion exchange membrane used in the present invention is made of a polymer containing a cation exchange group such as a carboxyl group, a sulfonic acid group, a phosphonic acid group, or a phenolic hydroxyl group, and such polymers include fluorine-containing polymers. It is particularly preferable to employ combination. Examples of fluorine-containing polymers containing ion-exchange groups include those that react with vinyl monomers such as tetrafluoroethylene and chlorotrifluoroethylene and ion-exchange groups such as sulfonic acid, carboxylic acid, and phosphoric acid groups, or that can be converted into ion-exchange groups. A copolymer with a perfluorinated vinyl monomer having a functional group is preferred.
Also usable are trifluoroethylene membrane polymers into which ion exchange groups such as sulfonic acid groups have been introduced, and styrene divinylbenzene into which sulfonic acid groups have been introduced. Among these, it is preferable to use polymers having the following structures (a) and (b), respectively. (a) (−CF 2 −CXX′)−
【式】
ここでXはF,Cl,H又は−CF3であり、X′はX
又はCF3(CF2)mであり、mは1〜5であり、
Yは次のものから選ばれる。
(−(CF2)−x−A,−O(−CF2)−xA,
x,y,zは共に1〜10であり、Z,Rfは−F
又は−C1〜10のパーフルオロアルキル基から選
ばれた基である。
Aは−COOM,−SO3M又は−CN,−COF,−
SO2F,−COOR1,−COOM,−CONR2R3,−
SO2NR2R3等の加水分解若しくは中和により、−
COOM又は−SO3Mに転換し得る官能基を示す。
R1はC1〜10のアルキル基、Mは水素又はアルカ
リ金属又は第4級アンモニウム基であり、R2,
R3は、H又はC1〜10のアルキル基を示す。
そして、本発明において、これら共重合体から
成る乾燥樹脂1g当りの膜内カルボン酸基濃度が
0.5〜4.0ミリ当量である含弗素陽イオン交換膜を
用いる場合には、特に本発明の所期の目的を十分
達成し得る事が見出された。
そして、上記乾燥樹脂当りのカルボン酸基濃度
が0.8〜2.0ミリ当量を採用する場合には、本発明
の目的を十分且つ安定して、特に性能の持続性、
耐久性を大になし得るので好ましい。そして、か
かるイオン交換容量を達成するには、上記(イ)及び
(ロ)の重合単位から成る重合体の場合好ましくは(ロ)
の重合単位が1〜40モル%、特に3〜20モル%で
あるのが適当である。
本発明に用いられる好ましい陽イオン交換膜
は、多くの場合、非架橋性の共重合体から構成さ
れ、又その分子量は、好ましくは約10万〜200
万、特に15万〜100万が好ましい。又、上記イオ
ン交換膜を形成する重合体を製造するには、種々
の方法が採用できるが、好ましくは(イ)、(ロ)の各単
量体の一種以上を用い、更に必要により第三の単
量体をも共重合することにより、製造することが
できる。例えば、第三の単量体としてはCF2=
CFORf(RfはC1〜10のパーフルオロアルキル
基)を選択することより、得られる膜に可撓性を
付与したり、或はCF2=CF−CF=CF2,CF2=
CFO(CF2)1〜3CF=CF2等のジビニルモノマー
を併用することにより、得られる共重合体を架橋
せしめ、膜に機械的強度を付与することもでき
る。
弗素化オレフイン単量体と、イオン交換基若し
くは該基に転換し得る官能基を有する重合能ある
単量体、更には第三の単量体との共重合は既知の
任意の手段で行なわれる。即ち、必要に応じ例え
ばハロゲン化炭化水素等の溶媒を用い、触媒重
合、熱重合、放射線重合等により重合し得る。
又、重合体からイオン交換膜に製膜する手段も特
に製限はなく、例えばプレス成形、ロール成形、
押出し成形、溶液流延法、デイスパージヨン成
形、粉末成形等適宜公知の手段を採用し得る。
かくして得られる膜は、その厚さが50〜500
μ、好ましくは100〜400μにせしめるのが好まし
い。又、重合体の製膜工程に相前後し、好ましく
は製膜後に共重合性がイオン交換基そのものでは
なく、該基に転換し得る官能基の場合には、それ
に応じた適宜な処理により、これらの官能基がイ
オン交換基に転換される。例えば−CN,−
COF,−SO2F,−COOR1(M,R1〜R3は上記と
同じ)の場合には、酸又はアルカリのアルコール
溶液により加水分解又は中和せしめてカルボン酸
基に転換し、又官能基が二重結合の場合には
COF2と反応せしめてカルボン酸基に転換され
る。
更に、本発明に用いられる陽イオン交換膜は、
必要に応じ製膜時にポリエチレン、ポリプロピレ
ン等のオレフインの重合体、好ましくはポリテト
ラフルオロエチレン、エチレンとテトラフルオロ
エチレンとの共重合体等の含弗素重合体を混合し
て成形することできる。
又、金属の線や網、合成樹脂の網等の補強材に
よつて補強したり、寸法安定性を付与した陽イオ
ン交換膜を用いることもできる。
なお、第1図は、本発明のイオン交換膜電解槽
の概略説明図である。第1図において、1はイオ
ン交換膜であり、2,3はそれぞれイオン交換膜
に結合して形成せしめられた電極活性を有しない
陽極側及び陰極側の多孔質層である。
これらの多孔質層には、好ましくは目の細かい
陽極体4及び陰極体5が接触される。目の細かい
陽極体、陰極体には、それぞれ目が粗い陽極体6
及び陰極体7が積層され、目の細かい陽極体及び
陰極体を保持するようにされる。
塩化アルカリ電解の場合、陽極室には塩化アル
カリ水溶液(MCl+H2O)が供給され、一方陰極
室には水(H2O)又は稀釈苛性アルカリが供給さ
れる。陽極では電解により塩素が発生するととも
に、アルカリ金属イオン(M+)がイオン交換膜
を通じて陰極室に移行する。陰極室では電解によ
り水素が発生するとともに、水酸イオンが生成さ
れる。かかる水酸イオンは、陽極から移行したア
ルカリ金属イオンと反応し、苛性アルカリが生成
される。
以上は、本発明を特に塩化アルカリ水溶液の電
解する電解槽として説明したが、本発明の電解槽
はこれ以外の水電解、塩酸等のハロゲン化水素水
溶液電解及び炭酸アルカリ水溶液の電解槽として
も同様に使用できることはもちろんである。
以下本発明について更に具体的に説明する。
実施例 1
酸化チタン10g、粒径1μ以下のポリテトラフ
ルオロエチレン1.0g、水10c.c.及びイソプロピル
アルコール10c.c.を混合後、混練してペーストを得
た。該ペーストをイオン交換容量が1.45meq/g
乾燥樹脂、厚さ220μを有するポリテトラフルオ
ロエチレンとCF2=CFO(CF2)3COOCH3との共
重合体からなる陽イオン交換膜の一面にスクリー
ン印刷し、酸化チタンが1.5mg/cm2含まれる多孔
質層を得た。
次にイオン交換膜のもう一方の面に同様にし
て、酸化鉄を1mg/cm2の割合で含む多孔率90%の
多孔質層を付着させた。その後150℃、20Kg/cm2
の条件下でこれらの多孔質層をイオン交換膜に圧
着してから、90℃、25重量%の苛性ソーダ水溶液
に16時間浸漬して、前記イオン交換膜を加水分解
した。
次に前記の酸化チタンから成る多孔質層に陰極
体として全体の大きさが20cm×25cmの短径2mm、
長径5mm、線径0.3mm、厚さ0.3mmの平滑なニツケ
ルエクスパンデツドメタルと短径10mm、長径20
mm、線径2.0、厚さ2.0mmの平滑なニツケルエクス
パンデツドメタルを積層した陰極体を細い目のエ
クスパンデツドメタルを酸化チタンから成る多孔
質層に向けて押しあてた。また酸化ルテニウム−
酸化イリジウム−酸化チタン(3:1:4)が被
覆され、材質がチタンである以外は、いずれも上
記陰極体と同じ形状、寸法をもつ2枚のエキスパ
ンデツドメタルの積層物から陽極体を酸化鉄から
なる多孔質層に細い目のエクスパンデツドメタル
側を押しあてた。
次にこのような構成物を使用して陽極室に5N
−NaCl水溶液を陰極室に水を供給し、陽極液中
の塩化ナトリウム濃度を4Nに、陰極液中の苛性
ソーダ濃度を35重量%に保ちつつ電解を行い、以
下の結果を得た。
電流密度(A/dm2) 槽電圧(V)
20 2.96
40 3.20
又、電流密度40A/dm2で電解を実施した場合
の苛性ソーダ生成の電流効率は93%であつた。
実施例 2
実施例−1と同にして、それぞれれ陽極側、陰
極側に金属チタンと酸化タンタルからなる多孔質
層を結合したイオン交換膜を使用し、それぞれ実
施例−1で使用した電解体の積層物を多孔質面に
接触させずに、いずれも多孔質面から1.5mmの間
隔をあけて配置し電解をした以外は実施例−1と
全く同様にして電解を行ない、以下の結果を得
た。
電流密度(A/dm2) 槽電圧(V)
20 3.08
40 3.35
又、電流密度40A/dm2の電解を実施した場合
の苛性ソーダ生成の電流効率は94.5%であつた。
比較例
実施例1と同様なイオン交換膜構造体を使用
し、陰極に20メツシユのニツケル金網と50メツシ
ユの穴で開口率を60%とした厚さ5mmのニツケル
製目皿を積層したものを前者がイオン交換膜に接
触するように配置し、同様に陽極には酸化ルテニ
ウム−酸化イリジウム−酸化チタンン(3:1:
4)で被覆した同様のチタン金網(20メツシユ)
及びチタン目皿(50メツシユ)を使用し、前者が
イオン交換膜に接触するように配置した以外は実
施例と全く同様にして電解を行ない、以下の結果
を得た。
電流密度(A/dm2) 槽電圧(V)
20 3.03
40 3.31
又、電流密度40A/dm2の電解を実施した場合
の苛性ソーダ生成の電流効率は86%であつた。[Formula] Here, X is F, Cl, H or -CF 3 , and X' is
or CF 3 (CF 2 )m, where m is 1 to 5,
Y is selected from the following: (-( CF2 ) -x -A,-O( -CF2 ) -xA , x, y, z are all 1 to 10, and Z, R f is -F
or a group selected from -C1-10 perfluoroalkyl groups. A is −COOM, −SO 3 M or −CN, −COF, −
SO 2 F, −COOR 1 , −COOM, −CONR 2 R 3 , −
By hydrolysis or neutralization of SO 2 NR 2 R 3 , etc., -
Indicates a functional group that can be converted to COOM or -SO3M .
R 1 is a C 1-10 alkyl group, M is hydrogen, an alkali metal, or a quaternary ammonium group, R 2 ,
R3 represents H or a C1-10 alkyl group. In the present invention, the concentration of carboxylic acid groups in the film per gram of dry resin made of these copolymers is
It has been found that when a fluorine-containing cation exchange membrane having a fluorine content of 0.5 to 4.0 milliequivalents is used, the intended purpose of the present invention can be particularly fully achieved. When the concentration of carboxylic acid groups per dry resin is 0.8 to 2.0 milliequivalents, the objects of the present invention can be sufficiently and stably achieved, and in particular, the durability of performance can be improved.
It is preferable because it can increase durability. In order to achieve such ion exchange capacity, the above (a) and
In the case of a polymer consisting of polymerized units of (b), preferably (b)
Suitably, the proportion of polymerized units is 1 to 40 mol %, particularly 3 to 20 mol %. Preferred cation exchange membranes used in the present invention are often composed of non-crosslinkable copolymers, and their molecular weight is preferably about 100,000 to 200,000.
10,000, especially preferably 150,000 to 1,000,000. Various methods can be used to produce the polymer forming the ion exchange membrane, but preferably one or more of the monomers (a) and (b) are used, and if necessary, a third monomer is used. It can also be produced by copolymerizing the monomers. For example, as the third monomer, CF 2 =
By selecting CFOR f (R f is a C 1-10 perfluoroalkyl group), flexibility can be imparted to the obtained film, or CF 2 =CF−CF=CF 2 , CF 2 =
By using a divinyl monomer such as CFO(CF 2 ) 1-3 CF=CF 2 in combination, the resulting copolymer can be crosslinked and mechanical strength can be imparted to the membrane. Copolymerization of the fluorinated olefin monomer and a polymerizable monomer having an ion exchange group or a functional group convertible into the group, and further a third monomer can be carried out by any known method. . That is, polymerization can be carried out by catalytic polymerization, thermal polymerization, radiation polymerization, etc., using a solvent such as a halogenated hydrocarbon, if necessary.
Furthermore, there is no particular limit to the method for forming an ion exchange membrane from a polymer, such as press molding, roll molding,
Any known means such as extrusion molding, solution casting, dispersion molding, powder molding, etc. may be employed as appropriate. The thickness of the membrane thus obtained is between 50 and 500 mm.
μ, preferably 100 to 400 μ. In addition, if the copolymerizability is not the ion exchange group itself but a functional group that can be converted into the group before or after the polymer film formation process, preferably after film formation, by appropriate treatment according to the copolymerizability, These functional groups are converted into ion exchange groups. For example −CN, −
In the case of COF, -SO 2 F, -COOR 1 (M, R 1 to R 3 are the same as above), it is converted into a carboxylic acid group by hydrolysis or neutralization with an acid or alkaline alcohol solution, or When the functional group is a double bond
It is converted into a carboxylic acid group by reacting with COF 2 . Furthermore, the cation exchange membrane used in the present invention is
If necessary, during film formation, an olefin polymer such as polyethylene or polypropylene, preferably a fluorine-containing polymer such as polytetrafluoroethylene or a copolymer of ethylene and tetrafluoroethylene, may be mixed and molded. Further, it is also possible to use a cation exchange membrane reinforced with a reinforcing material such as a metal wire, net, or a synthetic resin net, or provided with dimensional stability. Note that FIG. 1 is a schematic explanatory diagram of the ion exchange membrane electrolytic cell of the present invention. In FIG. 1, 1 is an ion exchange membrane, and 2 and 3 are porous layers on the anode side and the cathode side, respectively, which have no electrode activity and are bonded to the ion exchange membrane. These porous layers are preferably contacted with a fine-mesh anode body 4 and a cathode body 5. The fine-mesh anode body and cathode body each have a coarse-mesh anode body 6
and cathode body 7 are laminated to hold the fine-mesh anode body and cathode body. In the case of alkaline chloride electrolysis, the anode chamber is supplied with an aqueous alkali chloride solution (MCl+H 2 O), while the cathode chamber is supplied with water (H 2 O) or diluted caustic alkali. At the anode, chlorine is generated by electrolysis, and alkali metal ions (M + ) are transferred to the cathode chamber through the ion exchange membrane. In the cathode chamber, hydrogen is generated by electrolysis, and hydroxide ions are also generated. These hydroxide ions react with alkali metal ions transferred from the anode to produce caustic alkali. In the above, the present invention has been particularly described as an electrolytic cell for electrolyzing an aqueous alkali chloride solution, but the electrolytic cell of the present invention can be similarly applied to other water electrolysis, electrolysis of an aqueous hydrogen halide solution such as hydrochloric acid, and an electrolytic cell for an aqueous alkali carbonate solution. Of course, it can be used for. The present invention will be explained in more detail below. Example 1 10 g of titanium oxide, 1.0 g of polytetrafluoroethylene with a particle size of 1 μm or less, 10 c.c. of water, and 10 c.c. of isopropyl alcohol were mixed and kneaded to obtain a paste. The paste has an ion exchange capacity of 1.45meq/g
A dry resin, screen printed on one side of a cation exchange membrane made of a copolymer of polytetrafluoroethylene and CF 2 = CFO (CF 2 ) 3 COOCH 3 with a thickness of 220 μ, and titanium oxide of 1.5 mg/cm 2 A porous layer containing was obtained. Next, a porous layer containing iron oxide at a rate of 1 mg/cm 2 and having a porosity of 90% was deposited on the other side of the ion exchange membrane in the same manner. Then 150℃, 20Kg/cm 2
These porous layers were pressed onto the ion exchange membrane under the following conditions, and then immersed in a 25% by weight aqueous sodium hydroxide solution at 90° C. for 16 hours to hydrolyze the ion exchange membrane. Next, the above porous layer made of titanium oxide was used as a cathode body with a short diameter of 2 mm and a total size of 20 cm x 25 cm.
Smooth nickel expanded metal with a long diameter of 5 mm, wire diameter of 0.3 mm, and thickness of 0.3 mm, a short diameter of 10 mm, and a long diameter of 20 mm.
A cathode body made of a layered layer of smooth nickel expanded metal with a wire diameter of 2.0 mm, a wire diameter of 2.0 mm, and a thickness of 2.0 mm was pressed against a porous layer made of titanium oxide with the expanded metal of fine mesh. Also, ruthenium oxide
The anode body is made from a laminate of two expanded metals that are coated with iridium oxide-titanium oxide (3:1:4) and have the same shape and dimensions as the cathode body above, except that the material is titanium. The narrow expanded metal side was pressed against the porous layer made of iron oxide. Then use such a configuration to add 5N to the anode chamber.
Water was supplied to the -NaCl aqueous solution into the cathode chamber, and electrolysis was carried out while maintaining the sodium chloride concentration in the anolyte at 4N and the caustic soda concentration in the catholyte at 35% by weight, and the following results were obtained. Current density (A/dm 2 ) Cell voltage (V) 20 2.96 40 3.20 Furthermore, when electrolysis was carried out at a current density of 40 A/dm 2 , the current efficiency for producing caustic soda was 93%. Example 2 In the same manner as in Example-1, an ion exchange membrane in which a porous layer made of titanium metal and tantalum oxide was combined was used on the anode side and the cathode side, respectively, and the electrolyte used in Example-1 was used. Electrolysis was carried out in exactly the same manner as in Example 1, except that the laminates were placed at a distance of 1.5 mm from the porous surface without contacting the porous surface, and the following results were obtained. Obtained. Current density (A/dm 2 ) Cell voltage (V) 20 3.08 40 3.35 In addition, when electrolysis was carried out at a current density of 40 A/dm 2 , the current efficiency for producing caustic soda was 94.5%. Comparative Example The same ion exchange membrane structure as in Example 1 was used, and the cathode was laminated with a 5 mm thick nickel perforated plate with 20 mesh nickel wire mesh and 50 mesh holes with an aperture ratio of 60%. The former was placed in contact with the ion exchange membrane, and similarly the anode was made of ruthenium oxide - iridium oxide - titanium oxide (3:1:
4) Similar titanium wire mesh coated with (20 mesh)
Electrolysis was carried out in exactly the same manner as in the example except that a titanium perforated plate (50 mesh) and a titanium perforated plate (50 mesh) were placed in contact with the ion exchange membrane, and the following results were obtained. Current density (A/dm 2 ) Cell voltage (V) 20 3.03 40 3.31 Furthermore, when electrolysis was carried out at a current density of 40 A/dm 2 , the current efficiency for producing caustic soda was 86%.
第1図は本発明の電極体を使用した電解槽の概
略説明図である。
1……イオン交換膜、2,3……それぞれ陽極
側多孔質層、陰極側多孔質層、4,5……それぞ
れ目の細かい陽極、陰極、6,7……それぞれ目
の粗い陽極、陰極。
FIG. 1 is a schematic explanatory diagram of an electrolytic cell using the electrode body of the present invention. 1... Ion exchange membrane, 2, 3... Porous layer on the anode side, porous layer on the cathode side, respectively, 4, 5... Fine anode, cathode, respectively, 6, 7... Coarse anode, cathode, respectively. .
Claims (1)
ないガス及び液透過性の多孔質層に、電極体を接
触させるか又はその近傍に配置させたた電解槽で
あつて、上記電極体が、目が細かく線径の細いエ
キスパンデツドメタル又は金網から、順次目が粗
く線径の太いエキスパンデツドメタル又は金網を
複数枚積層して構成されたことを特徴とするイオ
ン交換膜電解槽。1. An electrolytic cell in which an electrode body is placed in contact with or in the vicinity of a gas and liquid permeable porous layer having no electrode activity formed on the surface of an ion exchange membrane, wherein the electrode body is An ion-exchange membrane electrolytic cell characterized in that it is constructed by laminating a plurality of expanded metals or wire meshes with fine meshes and thin wire diameters, followed by a plurality of expanded metals or wire meshes with coarse meshes and thick wire diameters.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP55116404A JPS5741387A (en) | 1980-08-26 | 1980-08-26 | Electrode body for electrolytic cell |
US06/381,746 US4661218A (en) | 1979-11-27 | 1982-05-24 | Ion exchange membrane cell and electrolysis with use thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP55116404A JPS5741387A (en) | 1980-08-26 | 1980-08-26 | Electrode body for electrolytic cell |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5741387A JPS5741387A (en) | 1982-03-08 |
JPS6123875B2 true JPS6123875B2 (en) | 1986-06-07 |
Family
ID=14686203
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP55116404A Granted JPS5741387A (en) | 1979-11-27 | 1980-08-26 | Electrode body for electrolytic cell |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5741387A (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4876724A (en) * | 1988-04-29 | 1989-10-24 | Toshiba America, Inc. | Personal sound system |
JP6208380B2 (en) * | 2015-07-29 | 2017-10-04 | 株式会社東芝 | Electrode for electrolysis, electrode unit, and electrolysis apparatus |
CN206768237U (en) * | 2015-09-15 | 2017-12-19 | 株式会社东芝 | Electrode, electrode unit and electrolysis unit |
-
1980
- 1980-08-26 JP JP55116404A patent/JPS5741387A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS5741387A (en) | 1982-03-08 |
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