	US 11,702,769 B2
	Stabilized fiber, method of producing the same, and method of producing carbon fiber
Takuya Morishita, Nagakute (JP); Mamiko Narita, Nagakute (JP); Makoto Mouri, Nagakute (JP); Yoshihiro Kikuzawa, Nagakute (JP); Hideyasu Kawai, Toyota (JP); and Nozomu Shigemitsu, Nissin (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, Nagakute (JP)
Filed by TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, Nagakute (JP)
Filed on Sep. 14, 2020, as Appl. No. 17/19,526.
Claims priority of application No. 2019-170488 (JP), filed on Sep. 19, 2019.
Prior Publication US 2021/0087717 A1, Mar. 25, 2021
Int. Cl. D01F 9/22 (2006.01); C04B 14/38 (2006.01)

CPC D01F 9/225 (2013.01) [C04B 14/386 (2013.01); D10B 2101/12 (2013.01)]

8 Claims

1. A method of producing a stabilized fiber, comprising

performing a heat treatment on an acrylamide polymer fiber under an oxidizing atmosphere in a stabilization treatment temperature range of 200° C. to 500° C. while applying a tension of 0.07 mN/tex to 15 mN/tex,

wherein the heat treatment is performed until an intensity ratio of a G peak near 1,590 cm⁻¹to a D peak near 1,360 cm⁻¹in a Raman spectrum on a side of the acrylamide polymer fiber becomes 0.5 or more,

wherein an acrylamide polymer used in the acrylamide polymer fiber is a homopolymer of an acrylamide monomer or a copolymer of an acrylamide monomer and other polymerizable monomers in which a content of the acrylamide monomer unit in the copolymer is 50 mol % or more.