POROUS HOLLOW FIBER MEMBRANE

PROBLEM TO BE SOLVED: To provide: a porous hollow fiber membrane, which can be properly used in a processing device of clean water, drinking water or various aqueous fluids such as seawater, in which the timely reduction of performance while having excellent fraction characteristics and penetrability is suppressed, and which is excellent in the recoverability, separation characteristics, filtration stability and mechanical strength of membrane separation characteristics due to washing; and a manufacturing method therefor.SOLUTION: There is provided: a porous hollow fiber membrane having a porous layer made of a thermoplastic resin in at least an external surface and in the vicinity thereof. In the porous hollow fiber membrane, an average pore diameter (Ad) from the surface of a sectional structure to a depth of 1 μm is 0.6 or less of an average core diameter (Bd) of a depth of 2 μm to 3 μm; and a manufacturing method for the membrane.SELECTED DRAWING: Figure 12 【課題】浄水処理、飲料水の処理、海水除濁等の種々の水性流体の処理装置に好適に使用することができ、優れた分画特性及び透過性を有しながら、経時的な性能の低下が抑制され、洗浄による膜分離特性の回復性、分離特性、濾過安定性及び機械的強度に優れた多孔質中空糸膜並びにその製造方法を提供する。【解決手段】少なくとも外表面及びその近傍に熱可塑性樹脂からなる多孔質層を有する多孔質中空糸膜であって、断面構造における表面から深さ１μｍまでの平均孔径（Ａｄ）が、深さ２μｍから３μｍまでの平均孔径（Ｂｄ）の０．６以下である多孔質中空糸膜及びその製造方法である。【選択図】図１２