Hollow fiber membrane and method for manufacture thereof

摘要

A porous hollow fiber membrane, comprising a polyolefin hollow fiber membrane of an annular cross section of substantial circle 150 to 300 mu m in inside diameter and 10 to 150 mu m in wall thickness, said hollow fiber membrane forming on the inner wall side thereof a tight layer of intimately bound fine polyolefin particles and on the outer wall side thereof a porous texture of fine polyolefin particles bound in chains and containing fine pores extended continuously form said inner wall side to said outer wall side.