Patent ID: 11939499
Assignee: TOYOBO CO., LTD.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  G | IPC C  G

Claim 0:
1. A hard coating film for a foldable display, comprising:
a polyester film having a thickness of from 10 μm to 100 μm; and
an adhesive layer formed on at least one surface of the polyester film,
wherein the polyester film satisfies the following conditions:
(1) a refractive index in a bending direction is from 1.591 to 1.606;
(2) a refractive index in a folding portion direction is from 1.670 to 1.700;
(3) a refractive index in a thickness direction is 1.520 or less; and
(4) a density is 1.380 g/cm3 or more,

wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded,
wherein the adhesive layer has a thickness of from 1 μm to 50 μm,
wherein the polyester film is a biaxially stretched polyethylene terephthalate film, and
wherein the polyester film comprises an easy-to-adhere layer on at least one surface thereof and a hard coating layer having a thickness of from 1 μm to 50 μm arranged on the polyester film at least on an opposite side to a side of the hard coating film having the adhesive layer.