Toyo Boseki Kabushiki Kaisha

Toyobo Co., Ltd.

Satoru Ashitaka

Noriko Monden

Toru Uenishi

Noriaki Kato

Hideyuki Yokota

Hirofumi Ogawa

A porous hollow fiber membrane is provided for the treatment of a protein-containing liquid, which can effectively separate and remove a substance such as a small diameter virus, and which can allow effective permeation of a useful substance to be recovered such as protein in high concentration. The porous hollow fiber membrane has an asymmetric structure having a dense layer in an outer layer only and contains a hydrophobic polymer and a first hydrophilic polymer, the surface and the porous part of the hollow fiber membrane are coated with a second hydrophilic polymer, the hydrophobic polymer is a polysulfone-type polymer, the first hydrophilic polymer is a copolymer of vinylpyrrolidone with vinyl acetate, and the second hydrophilic polymer is a polysaccharide or a polysaccharide derivative. The porous hollow fiber membrane is obtained by co-dissolving the hydrophobic polymer and the first hydrophilic polymer and then the second hydrophilic polymer is coated.

Porous hollow fiber membrane

An object of the present invention is to provide a porous hollow fiber membrane for the treatment of a protein-containing liquid where the substances to be removed such as small-sized virus contained in a solution can be efficiently separated and removed and, at the same time, useful substances to be recovered such as protein can be efficiently permeated and the decrease in the permeation characteristics thereof with elapse of time is small. The porous hollow fiber membrane for the treatment of a protein-containing liquid of the present invention is characterized in that the membrane comprises a hydrophobic polymer and a hydrophilic polymer, its permeability for pure water is 10 to 300 L/(h&#xb7;m&#xb7;bar) and, when a 0.5% immunoglobulin solution is subjected to filtration at a constant pressure of 1.0 bar for 60 minutes in dead-end filtration mode, its filtration time and accumulated amount of recovered filtrate are substantially in a linear relation.

Porous hollow fiber membrane for treatment of protein-containing liquid

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Otsu, Japan

Satoru Ashitaka