Yamaguchi University

Kuraray Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Mitsuru Higa

Atsushi Jikihara

Kenichi Kobayashi

Takahiro Nakashima

Shigeharu Takagi

Naoki Fujiwara

Takashi Wakui

Provided is an ion exchange membrane including an ionic vinyl alcohol polymer having a cation exchange group or an anion exchange group. The ion exchange membraneincludes a porous supportand the ionic vinyl alcohol polymer. The porous support is provided, in a thickness direction from one surface thereof, with an impregnated layerat least a part of which is impregnated with the ionic vinyl alcohol polymer. The ionic vinyl alcohol polymer includes an ionic vinyl alcohol polymer having an ion exchange group selected from a cation exchange group or an anion exchange group. The ion exchange membrane has a zeta potential value (&#x3b6;1) at one surface and a zeta potential value (&#x3b6;2) at the other surface, which are represented by the formula (1).(|&#x3b6;1|)&#x2212;|&#x3b6;2|)/|&#x3b6;1|&#x3c;0.5 (|&#x3b6;1|)&#x2265;|&#x3b6;2|)&#x2003;&#x2003;(1)

Ion exchange membrane, method for producing same, and electrodialyzer

Provided is a cation exchange membrane having a stable ion exchange performance during usage, being excellent in basic properties such as membrane resistance and ion transportation as well as strength, and useful for electrodialysis and a method for producing the same. The cation exchange membrane is composed of a polyvinyl alcohol copolymer including an anionic group-containing anionic polymer segment and a vinyl alcohol polymer segment, and having a microphase separation structure having a domain size (X) in a range from 0 nm&#x3c;X&#x2266;150 nm. The method is composed of forming a membrane from a polyvinyl alcohol copolymer which is adjusted to contain salts in a proportion that the salt weight (C) relative to the polyvinyl alcohol copolymer weight (P) is [(C)/(P)] of 4.5/95.5 or lower.

Cation exchange membrane and method for producing same

There is provided a multilayered charge-mosaic membrane having a porous supporting layer (A), a porous intermediate layer (B) and a charge-mosaic layer (C), wherein the porous supporting layer (A), the porous intermediate layer (B) and the charge-mosaic layer (C) are located in this order; the porous supporting layer (A) and/or the porous intermediate layer (B) are made of a fiber layer containing hydrophilic fibers; a thickness of the porous intermediate layer (B) is 0.1 to 100 &#x3bc;m; a porosity of the porous supporting layer (A) is larger than a porosity of the porous intermediate layer (B); the cationic and/or the anionic polymers constituting the charge-mosaic layer (C) is a polyvinyl alcohol having an ionic group. Thus, there is provided a multilayered charge-mosaic membrane having a large salt permeation flux and excellent mechanical strength.

Multilayered charge-mosaic membrane and manufacturing method therefor

There is provided an ion-exchange membrane comprising an ion-exchange layer made of a cationic polymer and/or an anionic polymer and a supporting layer, wherein the ion-exchange layer is formed on the supporting layer by printing. Such an ion-exchange membrane exhibits excellent anti-organic fouling and low membrane resistance, thereby high efficient and long-time stable electrodialysis can be achieved. Formation of the ion-exchange layer as a charge-mosaic layer consisting of the cationic polymer domains and the anionic polymer domains provides a charge-mosaic membrane exhibiting excellent electrolyte permselectivity and mechanical strength.

Ion-exchange membrane and method for producing same

A graft copolymer having a side chain graft-polymerized by atom transfer living radical polymerization (ATRP) on a main chain polymerized by organotellurium-mediated living radical polymerization (TERP), wherein the molecular weight distribution is such that Mw/Mn is 1.5 or less. The graft copolymer is also such that a main chain moiety mainly consisting of the main chain and a side chain moiety mainly consisting of the side chain have microphase-separated structures. The graft copolymer has a narrow molecular weight distribution and forms microphase-separated structures through self organization of hydrophobic and hydrophilic moieties.

Graft copolymer and process for producing the same

This invention provides a novel graft polymer that has excellent proton conductivity, is capable of regulating hydrogen permeability, methanol permeability, and the like, and can serve as a starting material for a polymer electrolyte membrane, which facilitates moisture balance control and efficient operation of a fuel cell. A polymer electrolyte membrane composed of such graft polymer is also provided. This graft polymer comprises a main chain comprising a hydroxyl group-containing polymer and a graft chain comprising a polymer containing a sulfonic acid group-containing monomer.

Growing community of inventors

Ube, Japan

Mitsuru Higa