Patent ID: 11970592
Assignee: SK IE TECHNOLOGY CO., LTD.
Field: Other special machines (Mechanical engineering)
Classification: CPC C | IPC C

Claim 0:
1. A window cover film comprising:
a polyamide-imide film prepared from a polyamide-imide base layer prepared from polymerization of 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, wherein the first fluorine-based aromatic diamine and the second fluorine-based aromatic diamine may be chemically the same or different, wherein the polyamide-imide film is prepared by applying the base layer onto a base material, drying the base layer in a plurality of drying regions to form a dried base layer, and stretching the dried base layer in a plurality of stretching regions; and
a hard coating layer formed on at least one surface of the base layer,
wherein a hybrid folding resistance capacity is 150,000 or more, the hybrid folding resistance capacity referring to the number n of times of repeated measurement on one surface in which a crack initially occurs when in-folding at a specific position of the window cover film against a cylinder having a radius of 5 mm at a rate of 60 cycles/min is repeatedly performed n times, and out-folding at the same position of the window cover film subjected to the in-folding, under the same conditions as those in the in-folding is repeatedly performed n times.