Patent ID: 11872530
Assignee: FRESENIUS MEDICAL CARE DEUTSCHLAND GMBH
Field: Chemical engineering (Chemistry)
Classification: CPC B  A | IPC A  B

Claim 0:
1. A hollow fiber membrane having a membrane material comprising a) a hydrophobic polymer comprising a polysulfone and b) a hydrophilic polymer comprising polyvinylpyrrolidone and c) at least one water-insoluble antioxidant, and wherein the hollow fiber membrane has a content of said polyvinylpyrrolidone of less than 5% (w/w) and wherein the hollow fiber membrane has a near-surface layer and a polyvinylpyrrolidone content in the near-surface layer of an inner lumen of the hollow fiber membrane amounts to 22% by weight or more pursuant to an XPS measurement method and wherein an elution of the hydrophilic polymer amounts to less than 4000*10−7 mg per individual fiber after being stored for a period of time of 30 days at 80° C. and <5% relative humidity, and wherein the hollow fiber membrane has a lumen-side and the hollow fiber membrane has a zeta potential on the lumen-side surface of −1 mV to less than −4 mV, wherein a peak height ratio of CNO— and SO2— amounts to 5.5 or higher on a surface layer of the inner lumen of the membrane as determined by TOF-SIMS.