POROESE HULE FIBRE AF REGENERERET CELLULOSE OG FREMGANGSMAADE TIL FREMSTILLING HERAF

摘要

A porous regenerated cellulose hollow fiber obtained by a micro-phase-separation method is described. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5x104, each of the average pore diameter D1 on the inner wall surface of the hollow fiber and the average pore diameter D2 on the outer wall surface is 0.02 to 10 mu m, the in-plane porosity Pr on the outer wall surface is at least 10%, and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length. The hollow fiber is prepared by a process characterized in that at the steps of extruding a cuprammonium solution of a cellulose from an annular spinning orifice and coagulating, regenerating and water-washing the extrudate, the spinning solution is extruded from an outer annular spinning orifice and a liquid having a coagulating action to the spinning solution is extruded from a central spinning orifice, and micro-phase-separation is caused to occur before the coagulation.