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

Abstract

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·m·bar) and the permeability for a 0.1% by weight solution of bovine γ-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 γ-globulin in a 20 mmol/L phosphate buffer is 30 to 100% of the permeability for a 0.1% by weight solution of bovine γ-globulin in a 20 mmol/L phosphate-buffered physiological saline solution.