	US 12,305,002 B2
	Polyimide-based film and window cover film using same
Minsang Park, Daejeon (KR); Hye Ri Kim, Daejeon (KR); Hyejin Kim, Daejeon (KR); Jinsu Park, Daejeon (KR); Seungmin Jeong, Daejeon (KR); and Yeongmin Jo, Daejeon (KR)
Assigned to SK Innovation Co., Ltd., Seoul (KR); and SK ie technology Co., Ltd., Seoul (KR)
Appl. No. 17/764,678
Filed by SK Innovation Co., Ltd., Seoul (KR); and SK ie technology Co., Ltd., Seoul (KR)
PCT Filed Sep. 29, 2020, PCT No. PCT/KR2020/013326 § 371(c)(1), (2) Date Mar. 29, 2022, PCT Pub. No. WO2021/066516, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 10-2019-0120519 (KR), filed on Sep. 30, 2019.
Prior Publication US 2022/0315702 A1, Oct. 6, 2022
Int. Cl. C08G 73/10 (2006.01); C08J 5/18 (2006.01); C08J 7/04 (2020.01); G02B 1/04 (2006.01); G02B 1/10 (2015.01)

CPC C08G 73/1039 (2013.01) [C08J 5/18 (2013.01); C08J 7/04 (2013.01); G02B 1/04 (2013.01); G02B 1/10 (2013.01); C08J 2333/24 (2013.01)]

10 Claims

1. A polyimide-based film of which a circular retardance value with respect to an omnidirectional angle of 0° to 360° is−30° to 30° when incident light passes through the polyimide-based film in a state in which a tilt angle of linear polarization of the incident light with respect to a thickness direction of the polyimide-based film is 0 to 60°,

wherein the polyimide-based film has a polyamide-imide structure, and

wherein the polyimide-based film includes a unit derived from a fluorine-based aromatic diamine, a unit derived from an aromatic dianhydride, a unit derived from an aromatic diacid dichloride, and a unit derived from a cycloaliphatic dianhydride.