PROCESS FOR PRODUCING AROMATIC POLYIMIDE FILAMENTS

摘要

Aromatic polyimide fibers having an enhanced mechanical strength are produced by a process comprising the steps of: preparing a spinning dope solution of at least one aromatic polyimide having 90 molar % or more of a recurring unit of the formula (I): wherein R is a divalent aromatic radical, in a phenolic solvent; converting the dope solution into at least one filamentary stream thereof; solidifying the filamentary dope solution stream by removing the solvent therefrom to provide at least one undrawn filament, and; drawing the undrawn filament at a temperature of 20 DEG to 600 DEG C. at a draw ratio of 1.5 to 5.0.