Asahi Glass Company, Limited

Other

Yoshio Sugaya

Haruhisa Miyake

Tatsuro Asawa

Hiroshi Toda

Yukio Matsumura

Hirofumi Horie

Ichiro Terada

Koji Suzuki

Hiroshi Mori

Manabu Suhara

Atsushi Watakabe

Masaaki Yamabe

Hirokazu Wakabayashi

Seiji Munekata

Hisao Kawazoe

Hirohisa Kubota

Masami Yamashita

Josho Kashiwame

Makoto Nakao

Yukio Jitsugiri

Yoshiharu Aoki

Motoo Fukui

Tetsugi Shimohira

Kiyonari Sanekata

Misaki Tada

Misaki Kanazawa

An anion exchange membrane comprising a resin phase which contains from 20 to 96 mass % of a polymer having repeating units represented by the following formula (1): wherein A is a Calkylene group or an alkyleneoxyalkyl group having a total carbon number of from 4 to 9, each of R, Rand Ris a hydrogen atom, a Calkyl group or a hydroxyalkyl group, and Xis an anion, and wherein any hydrogen atom bonded to the benzene ring may be substituted by an alkyl group or a halogen atom, and from 4 to 80 mass % of a thermoplastic polymer having no ion exchange groups, substantially uniformly.

Anion exchange membrane, process for its production and solution treating apparatus

A process for producing an anion exchange membrane, which comprises mixing from 25 to 95 mass % of a polymer having anion exchange groups or active groups convertible to anion exchange groups (hereinafter referred to as polymer 1), and from 5 to 75 mass % of a polymer having no anion exchange groups or no active groups convertible to anion exchange groups (hereinafter referred to as polymer 2), and forming the obtained composition into a membrane, said process including a step of cross-linking an aromatic ring of a repeating unit constituting polymer 1 with an aromatic ring of another repeating unit constituting polymer 1 or with a cross-linkable site of polymer 2, and in a case where polymer 1 is a polymer having active groups convertible to anion exchange groups, a step of converting the active groups to anion exchange groups.

Anion exchanger and process for producing anion exchange membrane

Heterogeneous anion exchanger

The present invention provides a cation exchange membrane which has excellent durability, a high limiting current density, a low direct current membrane resistance and excellent selectivity to monovalent cations. In the present invention, a cation exchange membrane excellent in selective permeability to monovalent cations is produced by bringing high molecular cations into contact with a surface of a cation exchange membrane in the presence of anions of an oxyacid or anions of an organic sulfonic acid.

Cation exchange membrane selectively permeable to monovalent cations and method for its production

Method for producing deionized water

An electro-regenerating type apparatus for producing deionized water, which comprises an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between an anode compartment provided with an anode and a cathode compartment provided with a cathode, demineralizing compartments compartmentalized with the anion exchange membranes on the anode side and compartmentalized with the cation exchange membranes on the cathode side, and concentrating compartments compartmentalized with the cation exchange membranes on the anode side and compartmentalized with the anion exchange membranes on the cathode side, the electrodialyzer having ion exchangers accommodated in the demineralizing compartments, wherein a porous anion exchanger layer having a porosity of from 20 to 95%, a maximum pore size of from 0.01 to 500 &mgr;m and a thickness of at least five times the maximum pore size and from 10 &mgr;m to 10 mm, is provided on the anode side of each anion exchange membrane.

Electro-regenerating type apparatus for producing deionized water

A method for hydrogen ion-selective electrodialysis, wherein from an aqueous solution containing hydrogen ions on an anode side, the hydrogen ions are selectively permitted to permeate through a membrane to a cathode side, wherein the membrane is a double layer ion exchange membrane comprising an anion exchanger layer on the anode side and a cation exchanger layer on the cathode side, and the anion exchanger layer has an ion exchange capacity of from 0.5 to 4 meq/g dry resin, a fixed ion concentration of from 1 to 10 meq/g H.sub.2 O, a thickness of from 0.1 to 150 .mu.m and an electrical resistance of at most 1 .OMEGA..multidot.cm.sup.2 as measured in a 0.5 mol/l sulfuric acid solution.

Method for hydrogen ion-selective electrodialysis

A method for separating and recovering an acid, which comprises contacting to one side of a diffusion dialysis membrane an acid solution containing an acid having an acid radical with a formula weight of at most 200 and impurities and to the other side of the membrane water or a dilute acid solution, to separate and recover the acid in the solution, wherein the diffusion dialysis membrane comprises a cation exchange membrane having certain specific properties or comprises a main layer of an anion exchanger and a surface layer of the cation exchange membrane having certain specific properties formed on the main layer at the side of which is contact with the acid solution.

Method for separating and recovering an acid

An anion exchanger consisting essentially of an aromatic polysulfone block copolymer of the formula: ##STR1## wherein Ar is ##STR2## or ##STR3## X is --SO.sub.2 --, ##STR4## --S-- or --O--, Y is --SO.sub.2 --, --S-- or --O--, Z is a single bond, --O--, --S--, --SO.sub.2 --, ##STR5## each of R.sub.1 to R.sub.9 which may be the same or different is a hydrocarbon group having from 1 to 8 carbon atoms, each of a to d is an integer of from 0 to 4, e is an integer of from 0 to 3, (f+g) is from 0 to 7, (h+i) is from 0 to 5, each of R.sub.10 and R.sub.11 is a hydrogen atom or a hydrocarbon group having from 1 to 6 carbon atoms, and each of m and n is an integer of from 2 to 200, provided m/n=100/1-1/10, and having anion exchange groups introduced to the aromatic rings of the copolymer.

Anion exchanger

A cation exchanger of polysulfone polymer consisting essentially of a sulfonated product of a polysulfone polymer having at least one chloromethyl (--CH.sub.2 Cl) or mercapto (--SH) group per molecule, or a cured product thereof, and having an ion exchange capacity of from 0.5 to 3.5 meq/g dry resin.

Cation exchanger

A method for producing an alkali metal hydroxide by electrolysis in an electrolytic cell comprising an anode compartment and a cathode compartment, which comprises supplying an aqueous alkali metal chloride solution to the anode compartment and withdrawing an aqueous alkali metal hydroxide solution from the cathode compartment, wherein a fluorine-containing cation exchange membrane comprising a first layer of an alkali resistant cation exchanger with a thickness of at least 5 .mu.m selected from the group consisting of the following (a), (b), and (c), and a second layer of a perfluorocarbon polymer having --CO.sub.2 M groups (wherein M is an alkali metal) and a water content of from 2 to 7% by weight in a 45 wt% NaOH aqueous solution with a thicknesss of at least 5 .mu.m, is disposed with the first layer facing the cathode compartment;

Method for producing an alkali metal hydroxide

A vapor permselective membrane consisting essentially of an ion exchange membrane made of a fluorine-containing polymer having a fixed ion concentration of from 1 to 6N, a water content of from 20 to 250% by weight and an ion exchange capacity of from 0.6 to 2.5 meq/g dry resin, the ion exchange membrane having a thickness of from 0.1 to 300 .mu.m and a moisture content of from 1 to 10% by weight, the permselective membrane having a water vapor permeation rate of at least 50 m.sup.3 /m.sup.2.atm.

Vapor permselective membrane

An electrolytic cation exchange membrane which comprises a first film made of a fluorinated polymer having cation exchange groups and containing a fibrillated tetrafluoroethylene polymer and a second film laminated thereon, made of a fluorinated polymer having carboxylic acid groups as its ion exchange groups, said first film having a greater thickness and smaller specific electric resistance than said second film.

Electrolytic cation exchange membrane

A multi-layered diaphragm for electrolysis, which comprises a porous layer of a fluorine-containing polymer having a pore diameter of from 0.05 to 10 .mu.m, a porosity of from 30 to 95% and a thickness of from 30 to 450 .mu.m and with its interior and anode-side surface being hydrophilic, and an ion exchange resin layer supported on the cathode side thereof and having a thickness thinner than the porous layer but of at least 5 .mu.m and an ion exchange capacity of from 0.5 to 2.0 meq/g dry resin, the total thickness being from 35 to 500 .mu.m.

Multi-layered diaphragm for electrolysis

An organic solution of a fluorinated copolymer having carboxylic acid groups comprises the copolymer of fluorinated ethylenically unsaturated monomer and a functional monomer having carboxylic acid group (--COOH group) dissolved in a hydrophilic organic solvent with a small amount of water.

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Yokohama, Japan

Yoshio Sugaya