US 12,227,421 B2
Graphite sheet produced from polyimide film having excellent orientation properties, and method for producing same
Kyung Su Kim, Iwol (KR); and Dong Young Won, Iwol (KR)
Assigned to PI Advanced Materials Co., Ltd., Iwol (KR)
Appl. No. 17/298,489
Filed by PI Advanced Materials Co., Ltd., Iwol (KR)
PCT Filed Oct. 28, 2019, PCT No. PCT/KR2019/014273
§ 371(c)(1), (2) Date May 28, 2021,
PCT Pub. No. WO2020/111529, PCT Pub. Date Jun. 4, 2020.
Claims priority of application No. 10-2018-0152538 (KR), filed on Nov. 30, 2018; and application No. 10-2019-0073519 (KR), filed on Nov. 30, 2018.
Prior Publication US 2022/0017371 A1, Jan. 20, 2022
Int. Cl. C01B 32/205 (2017.01); B29C 55/00 (2006.01); B29C 55/06 (2006.01); C08J 5/18 (2006.01); B29K 79/00 (2006.01); B29L 7/00 (2006.01)
CPC C01B 32/205 (2017.08) [B29C 55/005 (2013.01); B29C 55/06 (2013.01); C08J 5/18 (2013.01); B29K 2079/08 (2013.01); B29L 2007/008 (2013.01); C01P 2006/32 (2013.01); C08J 2379/08 (2013.01)] 3 Claims
 
1. A method for producing a graphite sheet, the method comprises a step of manufacturing a polyimide film by imidizing a polyamic acid having a weight-average molecular weight to number-average molecular weight (polydispersity index (PDI)) ratio of 1.8 to 3.0; and
a step of carbonizing, graphitizing, or carbonizing and graphitizing the polyimide film,
wherein the polyimide film has a molecular orientation ratio of 1.25 to 1.32 when the thickness of the polyimide film is 50 μm.