US 12,344,719 B2
Polyester film and foldable display device comprising the same
Gun Uk Kim, Gyeonggi-do (KR); Sang Min Choi, Gyeonggi-do (KR); and Jin-Seok Park, Gyeonggi-do (KR)
Assigned to SK MICROWORKS CO., LTD., Gyeonggi-do (KR)
Filed by SK microworks Co., Ltd., Gyeonggi-do (KR)
Filed on May 15, 2023, as Appl. No. 18/317,097.
Claims priority of application No. 10-2022-0073978 (KR), filed on Jun. 17, 2022.
Prior Publication US 2023/0407022 A1, Dec. 21, 2023
Int. Cl. C08J 5/18 (2006.01); B32B 17/10 (2006.01); B32B 27/08 (2006.01); B32B 27/28 (2006.01); B32B 27/36 (2006.01); G09F 9/30 (2006.01)
CPC C08J 5/18 (2013.01) [B32B 17/10 (2013.01); B32B 27/08 (2013.01); B32B 27/281 (2013.01); B32B 27/36 (2013.01); G09F 9/301 (2013.01); B32B 2250/02 (2013.01); B32B 2250/24 (2013.01); B32B 2307/412 (2013.01); B32B 2457/20 (2013.01); C08J 2367/02 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A polyester film, wherein when a first direction and a second direction perpendicular to each other are defined in the plane of the film, the yield elongation in at least one direction of the first direction and the second direction is 2.2 to 2.6%, and the thickness is 80 to 150 μm,
wherein the first direction is the longitudinal direction (MD), the second direction is the transverse direction (TD), and the stretching ratio in the longitudinal direction is 2.5 to 3.0, and
wherein the ratio (D2/D1) of the stretching ratio (D2) in the transverse direction (TD) to the stretching ratio (D1) in the longitudinal direction (MD) is 1.3 to 1.8.