Asahi Kasei Kogyo Kabushiki Kaisha

Asahi-Dow Limited

Tadashi Inoue

Sakae Tsushima

Tsumoru Kuwabara

Kiyotaka Yoshie

Tetsuro Tanaka

An ion exchange membrane reinforced by a woven reinforcing fabric is provided in which the difference between the thickness of the membrane at the crossover points where the warp and weft strands of the fabric cross each other and that at the window portions defined by the crossed warp and weft strands is not greater than 35 .mu.m. This membrane may be produced for example, by heating an assembly comprising at least two fluorinated polymer films each having pendant sulfonyl groups and/or carboxyl groups in a melt-fabricable form, and a woven reinforcing fabric sandwiched between the polymer films, and a support sheet laminated to the outermost polymer film, while applying a negative pressure to one side of the assembly that is remote from the support film, followed by converting the sulfonyl and/or carboxyl groups of the polymer films to sulfonate and/or carboxylate groups. This reinforced ion exchange membrane has flat film surfaces, thereby eliminating the danger of gas bubbles during chloralkali electrolysis which enables the cell voltage to be low, so that electric power consumption can be reduced.

Reinforced ion exchange membrane and a process for producing the same

A composite hydrophilic membrane comprising a very thin semipermeable hydrophilic membrane containing a sulfonic group and a polyethylenic microporous membrane containing sulfonic group. This hydrophilic membrane has specially high permeation rate of water and excellent separation ability. The composite hydrophilic membrane is manufactured by a method which comprises fusing a very thin membrane containing an ethylenic copolymer onto the surface of a polyethylenic microporous membrane or a polyethylenic membrane capable of being converted into a microporous membrane thereby forming a composite film, converting the resin film prior to and/or during and/or after sulfonation into a microporous membrane, and causing the composite film to react with a sulfonating agent. This method permits easy and efficient production of the composite hydrophilic membrane.

Composite hydrophilic membrane and method for manufacture thereof

A method and apparatus is provided for effecting dehydration of a water-containing substance held in a receiving compartment formed in an intervening space between a cathode and an anode by means of the electro-osmotic force of a microporous membrane. The apparatus of this invention has a semipermeable membranes disposed as diaphragms for the receiving compartment and the microporous membrane disposed on the anode side of the diaphragms arranged on the cathode side. It effects the dehydration of the water-containing substance by passing electric current between the two electrodes and discharges the water resulting from the dehydration through a space formed between the microporous membrane and the cathode side diaphragm. By this invention, various water-containing substances such as aqueous solutions, colloids, pastes, dispersions, and gels, which the conventional methods and apparatuses dehydrate with great difficulty, can be dehydrated at high speed with high efficiency.

Method and apparatus for dehydration of water-containing substance by

A vessel such as a glass bottle having a narrow-necked portion is protected by coating with a stretched film of crosslinked polyolefin resin having specific characteristics. The film holds the vessel very tightly through the shrink tension of the heat-shrunk film at the narrower part and through the elastic tension of the elongated film at the wider part. The protected vessel has excellent effect for preventing scattering of glass fragments at the time of breaking as well as good display effect and cap-seal effect. The coated film has also good printability.

Growing community of inventors

Fujisawa, Japan

Tadashi Inoue