PROCESS FOR PRODUCTION OF A POLYSULFONE TYPE SELECTIVELY PERMEABLE HOLLOW FIBER MEMBRANE MODULE

摘要

The present invention relates to a hollow fiber membrane module comprising polysulfone type selectively permeable hollow fiber membranes which contain a polysulfone-based resin and a hydrophilic polymer as main components, wherein
(A) the content of the hydrophilic polymer in the uppermost layer of the inner surface of said hollow fiber membrane is at least 1.1 time larger than the content of the hydrophilic polymer in the proximate layer of the inner surface of said membrane, and
(B) the content of the hydrophilic polymer in the uppermost layer of the outer surface of said hollow fiber membrane is at least 1.1 times larger than the content of the hydrophilic polymer in the uppermost layer of the inner surface of said membrane,
said hollow fiber membrane module being characterized in that
(C) said hollow fiber membrane module is exposed to a radioactive ray, on condition that the oxygen concentration of an ambient atmosphere around said hollow fiber membrane is from 0.001 to 0.1%, and that the moisture content of said hollow fiber membrane to the weight thereof is from 0.2 to 7 mass %. The present invention also relates to a process for manufacturing the same hollow fiber membrane module.