公开(公告)号：US20170283990A1

公开(公告)日：2017-10-05

申请号：US15425249

申请日：2017-02-06

Applicant: I.S.T Corporation

Inventor： Ryuta NAKAGAKI ,  Katsuki MORISHIMA ,  Koji MORIUCHI

IPC: D01F6/74 ,  C08G73/10 ,  B29C47/00

Abstract: The method for producing a polyimide fiber includes a coagulation step of forming a polyimide precursor fiber by extruding a polyimide precursor solution containing a polyimide precursor and a compound having an acid dissociation constant (pKa) of a conjugate acid in water at 25° C. of 6.0 to 10 inclusive and an octanol-water partition coefficient (Log P) at 25° C. of −0.75 to 0.75 inclusive into a poor solvent or nonsolvent for the polyimide precursor; and a heat drawing step of forming the polyimide fiber by drawing the polyimide precursor fiber while heating same. The polyimide fiber of the present disclosure has a physical property such that the coefficient of thermal expansion thereof is in the range of −15 ppm/K to 0 ppm/K inclusive.