Toyo Boseki Kabushiki Kaisha

Hirofumi Ogawa

Hideyuki Yokota

Noriaki Kato

Junsuke Morita

Noriko Monden

Satoru Ashitaka

Toru Uenishi

The purpose of the present invention is to provide a porous hollow fiber membrane that can efficiently separate and remove the substances to be removed such as small-particle virus contained in a solution and, at the same time, useful recovering substances such as protein can be efficiently permeated and the decrease of its transmission rate with elapse of time is small. The porous hollow fiber membrane of the present invention is characterized in that the filtration downstream surface thereof has dot-shaped or slit-shaped pores, the filtration upstream surface thereof is a network structure or a fine particle aggregate structure, the central region of the membrane is composed of a substantially homogeneous structure, the membrane wall is composed of a structure having substantially no macrovoids, the permeability for pure water is 10 to 300 L/(h&#xb7;m&#xb7;bar) and the permeability for a 0.1% by weight solution of bovine &#x3b3;-globulin is 30 to 100% of the permeability for pure water. Also, the hollow fiber membrane is characterized in that the permeability for a 0.1% by weight solution of bovine &#x3b3;-globulin in a 20 mmol/L phosphate buffer is 30 to 100% of the permeability for a 0.1% by weight solution of bovine &#x3b3;-globulin in a 20 mmol/L phosphate-buffered physiological saline solution.

Porous hollow fiber membrane and a porous hollow fiber membrane for the treatment of a protein-containing liquid

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

PURPOSE: To provide a polymeric porous hollow fiber membrane which exhibits excellent fractionation performance and excellent permeability in treatment of a variety of aqueous fluids and also shows sufficient strength when incorporated into a module or used to treat a fluid, and which is excellent in aging stability in these performances and characteristics and is also excellent in membrane performance recoverability by washing, and which is especially suitable for treatment of a polyphenol-containing beverage and is expected to effectively harmonize the flavor of such a beverage. SOLUTION: A polymeric porous hollow fiber membrane of the present invention is characterized in that This polymeric porous hollow fiber membrane is also characterized in that the adsorption of polyphenol per a surface area of 1 mdefined by the inner and outer surfaces of the membrane is from 50 to 500 mg.

Polymeric porous hollow fiber membrane

The present invention provides a hollow fiber membrane for treating liquids. When used for a hollow fiber membrane module for refining a fermented liquid such as beer or wine, the hollow fiber membrane exhibits a high filtration performance per unit area thereof, with reduced clogging of the membrane. The membrane performance is sufficiently recovered by washing. The present invention is a hollow fiber membrane for treating liquids, wherein a ratio of Flux 120 to Flux 30 is 0.45 or higher when filtration is performed by supplying a solution having a turbidity of 20 NTU into a hollow fiber membrane having an internal diameter of 500 to 1500 &#x3bc;m and a membrane thickness of 100 to 500 &#x3bc;m with a transmembrane pressure of 1.5 bar, the Flux 30 being flux 30 minutes after the start of the filtration, the Flux 120 being flux 120 minutes after the start of the filtration.

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Ohtsu, Japan

Hirofumi Ogawa