Patent ID: 11921546
Assignee: SK IE TECHNOLOGY CO., LTD.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  G  B | IPC B  C  G

Claim 11:
12. A polyimide-based film of which a modulus measured according to ASTM D882 is 5 GPa or more and a rate of change of the modulus, after the polyimide-based film is maintained under a high-temperature and high-humidity condition of 60° C. and 90% RH for 500 hours, is 10% or less,
wherein an in-plane phase difference and a phase difference in a thickness direction of the polyimide-based film measured at a wavelength of 550 nm are 173 nm to 200 nm and 5,797 nm to 6,000 nm, respectively, and
wherein the polyimide-based film is formed from a polyamide-imide-based resin prepared by polymerizing an amine-terminated polyamide oligomer derived from a first fluorine-based aromatic diamine and an aromatic diacid dichloride, with a second fluorine-based aromatic diamine, an aromatic dianhydride, and an alicyclic dianhydride.