US 12,281,213 B2
Polyamide-imide film, preparation method thereof, and display front plate and display device comprising same
Dae Seong Oh, Seoul (KR); Jung Hee Ki, Gyeonggi-do (KR); Sunhwan Kim, Incheon (KR); Han Jun Kim, Gyeonggi-do (KR); Jin Woo Lee, Seoul (KR); and Sang Hun Choi, Seoul (KR)
Assigned to SK MICROWORKS CO., LTD., Gyeonggi-do (KR)
Filed by SK microworks Co., Ltd., Gyeonggi-do (KR)
Filed on Jun. 26, 2020, as Appl. No. 16/913,092.
Claims priority of application No. 10-2019-0078286 (KR), filed on Jun. 28, 2019; and application No. 10-2019-0167993 (KR), filed on Dec. 16, 2019.
Prior Publication US 2020/0407521 A1, Dec. 31, 2020
Int. Cl. C08J 5/18 (2006.01); C08G 73/10 (2006.01); C08G 73/14 (2006.01); C08K 3/36 (2006.01)
CPC C08J 5/18 (2013.01) [C08G 73/1007 (2013.01); C08G 73/14 (2013.01); C08J 2379/08 (2013.01); C08K 3/36 (2013.01)] 7 Claims
 
1. A polyamide-imide film, which comprises a polyamide-imide polymer formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound; and a filler,
wherein the filler has an average particle diameter of 70 nm to 120 nm,
wherein, the dicarbonyl compound comprises a first dicarbonyl compound and a second dicarbonyl compound,
wherein the first dicarbonyl compound and the second dicarbonyl compound are structural isomers to each other,
wherein the dianhydride compound comprises 2,2′-bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), the first dicarbonyl compound is a compound having two carbonyl groups at the m-position, and the second dicarbonyl compound is a compound having two carbonyl groups at the p-position,
wherein the molar ratio of the dianhydride compound and the dicarbonyl compound is 2:98 to 45:55,
wherein a content of a residual solvent in the polyamide-imide film is 900 ppm or less,
wherein the FH value of the following Equation 1 is less than 0.3, and
wherein the IS value represented by the following Equation 3 is 5 to 100:

OG Complex Work Unit Math
wherein, in Equation 1, FC is the content (ppm) of the filler based on the total weight of the solids content in the polymer, and HZ stands for the haze (%) of the film,
IS=IM+RS/10  [Equation 3]
wherein, in Equation 3, IM stands for the number of moles of an imide repeat unit when the total number of moles of the imide repeat unit and an amide repeat unit in the film is 100; and RS stands for the content (ppm) of the residual solvent in the film.