Preoxidized fiber and process for producing the same

摘要

A preoxidized fiber suitable for producing carbon fiber, comprising preoxidizing an acrylic fiber having thereon an ammonium salt of a fatty ester represented by formula [A] and [B] <IMAGE> [A] <IMAGE> [B] wherein R1 is an aliphatic hydrocarbon group having from 11 to 17 carbon atoms; R2 and R3 can each be hydrogen, a lower alkyl group, a hydroxyethyl group, or an hydroxyisopropyl group; and X(-) is an anion. The preoxidized fiber produced from the acrylic fiber has very little coalescence, and therefore high-strength carbon fiber can be obtained from this preoxidized fiber.