	US 11,807,730 B2
	Composition for forming polyimide film for cover window, method for preparing the same, and use thereof
Cheol Min Yun, Daejeon (KR); and Hye Jin Park, 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 Jun. 15, 2022, as Appl. No. 17/841,177.
Claims priority of application No. 10-2021-0077760 (KR), filed on Jun. 16, 2021.
Prior Publication US 2023/0002576 A1, Jan. 5, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. B32B 27/28 (2006.01); C08G 73/10 (2006.01); C08J 7/04 (2020.01); C08J 5/18 (2006.01)

CPC C08J 7/0427 (2020.01) [B32B 27/281 (2013.01); C08G 73/1032 (2013.01); C08G 73/1039 (2013.01); C08G 73/1042 (2013.01); C08G 73/1064 (2013.01); C08J 5/18 (2013.01); B32B 2457/20 (2013.01); C08J 2379/08 (2013.01); C08L 2201/10 (2013.01); C08L 2203/16 (2013.01)]

18 Claims

1. A composition for forming a polyimide film for a cover window comprising:

a polyamic acid or a polyimide including a structural unit derived from a dianhydride and a structural unit derived from a diamine; and

a mixed solvent of an amide-based solvent and a hydrocarbon-based solvent, the hydrocarbon-based solvent being comprised at 10 to 40 wt % with respect to a total weight of the mixed solvent,

wherein the structural unit derived from a dianhydride comprises a structural unit derived from a compound represented by the following Chemical Formula 1 and a compound represented by the following Chemical Formula 2, and the structural unit derived from a diamine comprises a structural unit derived from a compound represented by the following Chemical Formula 3 and a compound represented by the following Chemical Formula 4:

8. A method for manufacturing a polyimide film for a cover window, the method comprising the steps of:

i) reacting a compound represented by the following Chemical Formula 1 and a compound represented by the following Chemical Formula 2 with a compound represented by the following Chemical Formula 3 and a compound represented by the following Chemical Formula 4 in the presence of an amide-based solvent to prepare a polyamic acid solution;

ii) further adding a hydrocarbon-based solvent to the polyamic acid solution to adjust crystallinity of the polyamic acid; and

iii) applying a composition for forming a polyimide film for a cover window obtained in step ii) on a substrate and performing curing,

wherein the hydrocarbon-based solvent in step ii) is further added so as to be 10 to 40 wt % with respect to a total weight of the amide-based solvent and the hydrocarbon-based solvent: