Patent ID: 8137800
Filing Date: 2012-03-20
Classification: B01D,D01D,D01F,Y10T

Abstract:
1. A process for producing a porous multilayer hollow fiber membrane by a hollow fiber molding nozzle with a circular discharge port, the process comprising discharging a molten mixture including a thermoplastic resin and an organic liquid from a circular discharge port of a hollow fiber molding nozzle to obtain a multilayer hollow fiber, and removing the organic liquid from the multilayer hollow fiber by extraction to obtain a porous multilayer hollow fiber membrane, the hollow fiber molding nozzle having two or more circular discharge ports which are disposed concentrically, molten mixtures which differ in composition being discharged from the adjacent discharge ports, the molten mixture discharged from at least one of the circular discharge ports further including an inorganic fine powder, and the inorganic fine powder being also removed from the resulting multilayer hollow fiber by extraction.