Patent ID: 7851024

Claim:
A method for manufacturing a porous membrane comprising a three-dimensional network structure and a spherical structure, comprising: simultaneously discharging, from a triple co-extrusion head comprising an external pipe, a middle pipe and an internal pipe, (A) a resin solution for forming the three-dimensional network structure from the external pipe or the middle pipe of the triple co-extrusion head, (B) a resin solution for forming the spherical structure from the external pipe of the triple co-extrusion head when the resin solution for forming the three-dimensional network structure is discharged from the middle pipe or from the middle pipe of the triple co-extrusion head when the resin solution for forming the three-dimensional network structure is discharged from the external pipe, and (C) a lumen forming fluid from the internal pipe of the triple co-extrusion head; and solidifying the resin solutions to form the porous membrane.