Composite hollow fiber membrane

摘要

Disclosed is a composite hollow fiber membrane having a composite structure consisting of a homogeneous thin film interposed between porous substrate layers wherein the ratio of the oxygen permeation flux to the nitrogen permeation flux of the membrane is not less than 1.1 and wherein, after the membrane has been immersed in chemical liquids according to JIS K 7114, the percentage change of the ratio is withinñ10%. This composite hollow fiber membrane can be used to degas chemical liquids without any liquid leakage.