Mitsubishi Rayon Company, Limited

Hiroyuki Fujiki

Toshinori Sumi

Kei Murase

Yasuo Hiromoto

Masaki Kurashina

Teruyuki Yamada

Katsuhiko Shinada

Masahiko Mizuta

Yuuichi Shirasu

Masakazu Minagawa

Masashi Teramachi

Disclosed is a method for manufacturing a composite porous film having a stable film quality and a desired hollow shape by controlling the entrance of a film-forming resin solution into a hollow part of a hollow reinforcement support. The method is provided with a step of adhering a film-forming resin solution to the outer peripheral surface of the hollow reinforcement support and thereby forming a film intermediate, a step of adhering a coagulating liquid to the outer peripheral surface of the film intermediate, and a step of flowing the coagulating liquid along the outer peripheral surface of the film intermediate so that at least a part of the outermost interface of the coagulating liquid in the circumferential direction is a free surface and thereby coagulating the film-forming resin solution adhering to the outer peripheral surface of the hollow reinforcement support.

Method for manufacturing a porous composite membrane

A method of manufacturing a porous film includes a decomposition step of introducing a porous film precursor which is formed by coagulating an undiluted film forming solution containing a hydrophilic polymer and a hydrophobic polymer, into a decomposition container; bringing a heated chemical containing an oxidizing agent into contact with the porous film precursor in the decomposition container; warming the porous film precursor in contact with the chemical; and decomposing the hydrophilic polymer remaining inside the porous film precursor using the oxidizing agent. An apparatus for manufacturing a porous film includes a decomposition device provided with the decomposition container.

Porous film manufacturing method and apparatus

Disclosed is a drying device for a hollow fiber membrane, including: a tubular drying member that is formed with an opening portion through which a hollow fiber membrane is input and output at at least one end thereof in a length direction, the hollow fiber membrane passing inside the tubular drying member while forming a gap between the hollow fiber membrane and an inner circumferential surface of the tubular drying member; and a gas supply unit that is formed on a side surface of the tubular drying member and supplies a drying gas into the tubular drying member. Thus, it is possible to dry the hollow fiber membrane in a short time at a low cost without the necessity of large equipment.

Drying device and drying method for hollow fiber membranes

A hollow porous membrane with a reduced cost and excellent separation characteristic, water permeability, and mechanical strength and a process of producing the hollow porous membrane with an excellent adhesive property between a support and a porous membrane layer at a low cost are provided. The hollow porous membrane includes a porous membrane layer in which dense layers are disposed in the vicinities of an outer surface and an inner surface. In the process of producing the hollow porous membrane, membrane-forming dopes of a first membrane-forming dope and a second membrane-forming dope, which contain the material of the porous membrane layer and a solvent, are successively applied and stacked onto the outer circumferential surface of a hollow support and the applied membrane-forming dopes are simultaneously coagulated. In the process of producing the hollow porous membrane, a porous membrane layer is formed by applying a membrane-forming dope containing a material of the porous membrane layer and a solvent to the outer circumferential surface of the hollow support and coagulating the applied dope, and a hollow braid obtained by circularly knitting a yarn formed of multi-filaments is used as the support.

Hollow porous membrane and process for producing the same

An object of the present invention is to provide a composite porous membrane, which has not only excellent filtration capacity, but also excellent adhesion between a porous membrane and a braid and mechanical properties, and a method for producing the composite porous membrane. The present invention relates to a composite porous membrane comprising a braid, and a membrane material; wherein the membrane material comprises a first porous layer comprising a dense layer which is arranged on the outer surface of the braid, and a second porous layer comprising a dense layer which is arranged on the first porous layer, and a method for producing the composite porous membrane.

Growing community of inventors

Otake, Japan

Hiroyuki Fujiki