Dispersion spinning core-shell fluoropolymers

摘要

A process is disclosed for dispersion spinning non-melt-processible fluoropolymer fiber in which a mixture of an aqueous dispersion of non-melt-processible fluoropolymer particles and an aqueous solution of a matrix polymer is formed. The non-melt-processible fluoropolymer particles have an SSG of less than about 2.40 and comprise a core of high molecular weight polytetrafluoroethylene and a shell of lower molecular weight polytetrafluoroethylene or modified polytetrafluoroethylene. The mixture is extruded into a coagulation bath containing a concentration of ions which coagulate the matrix polymer to form an intermediate fiber structure. The intermediate fiber structure is sintered to decompose the matrix polymer and coalesce the non-melt-processible fluoropolymer particles to form the fiber. The present invention also provides for spinning composition useful for the dispersion spinning of non-melt-processible fluoropolymer fiber.