US 11,654,665 B2
Window cover film and flexible display panel including the same
Jong Nam Ahn, Daejeon (KR); and Keon Hyeok Ko, Daejeon (KR)
Assigned to SK Innovation Co., Ltd., Seoul (KR); and SK ie technology Co., Ltd., Seoul (KR)
Filed by SK Innovation Co., Ltd., Seoul (KR); and SK IE Technology Co., Ltd., Seoul (KR)
Filed on Sep. 28, 2020, as Appl. No. 17/34,505.
Claims priority of application No. 10-2019-0120532 (KR), filed on Sep. 30, 2019.
Prior Publication US 2021/0094265 A1, Apr. 1, 2021
Int. Cl. B32B 27/28 (2006.01)
CPC B32B 27/281 (2013.01) [B32B 2307/40 (2013.01); B32B 2307/536 (2013.01); B32B 2307/54 (2013.01); B32B 2307/746 (2013.01); B32B 2457/20 (2013.01); Y10T 428/31721 (2015.04)] 14 Claims
OG exemplary drawing
 
1. A window cover film comprising sequentially stacked layers which are a base layer, a hard coating layer, and an anti-fingerprint layer, the base layer being formed of a polyamide-imide (PAI)-based resin, the hard coating layer comprises a silsesquioxane-based compound, and the anti-fingerprint layer being derived from a polyfunctional (meth)acrylate polymer, a polyfunctional urethane (meth)acrylate oligomer having 6 to 15 (meth)acrylic groups as a functional group, a polyfunctional (meth)acrylate monomer having 2 to 6 (meth)acrylic groups, and a fluorinated (meth)acrylate monomer, wherein the window cover film has a dynamic friction coefficient b of less than 0.15 as measured at a load of 200 g, a force of 5 N, and a rate of 100 mm/min using a parchment paper as an object to be rubbed, and a ratio of a static friction coefficient a to the dynamic friction coefficient b satisfies the following Expression 1,
0.5≤a/b≤1.5.  [Expression 1]