Mitsubishi Rayon Company, Limited

Masaki Kurashina

Toshinori Sumi

Hiroyuki Fujiki

Yasuo Hiromoto

Kei Murase

Osamu Maehara

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

The present invention of a method for producing a porous membrane including a solidification step of forming a porous membrane, and a heating step of drying the porous membrane, wherein the heating step includes at least a water reduction step of the porous membrane, the water reduction step uses a heating medium, and the temperature of the heating medium (T) satisfies a relation of t&#x3e;T, when Trepresents the heat deformation temperature of a membrane material. The present invention of a drying device of a porous membrane including a water reduction unit, and a final drying unit, wherein the drying device includes a membrane-surface-temperature measurement means for measuring the surface temperature of the porous membrane and the final drying unit, and a control means for controlling the temperature and/or the flow speed of the heating medium of the water reduction unit.

Method for producing porous membrane and drying device of porous membrane

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.

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Otake, Japan

Masaki Kurashina