US 11,905,354 B2
Method of preparing acrylonitrile-based copolymer for carbon fiber
Jong Gil Kim, Daejeon (KR); Chang Hun Kim, Daejeon (KR); Jeong Hun Cho, Daejeon (KR); Hyun Min Kim, Daejeon (KR); Joon Hee Cho, Daejeon (KR); and Hyo Yong Kim, Daejeon (KR)
Assigned to LG CHEM, LTD., Seoul (KR)
Appl. No. 17/266,078
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Nov. 1, 2019, PCT No. PCT/KR2019/014725
§ 371(c)(1), (2) Date Feb. 4, 2021,
PCT Pub. No. WO2020/091511, PCT Pub. Date May 7, 2020.
Claims priority of application No. 10-2018-0133737 (KR), filed on Nov. 2, 2018.
Prior Publication US 2021/0301051 A1, Sep. 30, 2021
Int. Cl. C08F 220/46 (2006.01); C01B 32/05 (2017.01); D01F 9/22 (2006.01)
CPC C08F 220/46 (2013.01) [C01B 32/05 (2017.08); D01F 9/22 (2013.01); C08F 2800/10 (2013.01)] 10 Claims
 
1. A method of preparing an acrylonitrile-based copolymer for a carbon fiber, the method comprising:
preparing a reaction solution including a monomer mixture and an organic solvent, wherein the monomer mixture comprises a sulfonate-based monomer represented by Chemical Formula 1, a carboxylic acid-based monomer, and an acrylonitrile-based monomer; and
subjecting the reaction solution to polymerization,
wherein the polymerization comprises:
primary polymerization of the reaction solution at a first temperature; and
secondary polymerization of the reaction solution at a second temperature higher than the first temperature,
wherein the monomer mixture comprises 0.55 to 1.6 mol % of the sulfonate-based monomer represented by Chemical Formula 1 based on a total molar amount of the monomer mixture:

OG Complex Work Unit Chemistry
wherein, in Chemical Formula 1,
R is hydrogen or a C1 to C3 linear alkyl group,
L is a C1 to C3 linear alkylene group, and
X is an alkali metal.