Cover window for display device and display device including the same
A cover window for a display device includes: a first film; a second film on the first film; and an adhesive layer between the first film and the second film. The adhesive layer has a lap shear modulus in a range of 20 kPa to 50 kPa.
1 . A bendable display device comprising:
a bendable display panel; and
a bendable cover window on the display panel, the cover window comprising:
a first film;
a second film on the first film; and
a first adhesive layer between the first film and the second film;
a coating layer on the cover window;
a second adhesive layer between the display panel and the cover window; and
an optical layer on the display panel,
wherein the cover window has a thickness in a range of 1 μm to 500 μm,
wherein the optical layer contacts the second adhesive layer,
wherein the first adhesive layer has a lap shear modulus in a range of 20 kPa to 50 kPa,
wherein the first adhesive layer has a modulus of elasticity that gradually varies along a thickness direction thereof,
wherein the first adhesive layer includes a first sub-layer, a second sub-layer, a third sub-layer, a fourth sub-layer, and a fifth sub-layer, and
wherein the modulus of elasticity of the first adhesive layer decreases, increases, or increases and then decreases from the first sub-layer to the fifth sub-layer.
2 . The bendable display device of claim 1 , wherein the optical layer comprises at least one of a phase delay layer or a polarization layer.
3 . The bendable display device of claim 1 , wherein the coating layer comprises a hard coating layer.
4 . The bendable display device of claim 1 , wherein the first film and the second film comprise a polyimide-based material.
5 . The bendable display device of claim 1 , further comprising:
a third film on the second film; and
a third adhesive layer between the second film and the third film.
6 . The bendable display device of claim 1 , wherein the first adhesive layer has a storage modulus in a range of 100 kPa to 10 MPa.
7 . The bendable display device of claim 6 , wherein the first adhesive layer has a loss modulus in a range of 100 kPa to 10 MPa.
8 . The bendable display device of claim 7 , wherein a ratio of the loss modulus to the storage modulus of the first adhesive layer is in a range of 0.01 to 100.
9 . The bendable display device of claim 1 , wherein the first adhesive layer has an adherence in a range of 500 gf/25 mm to 3000 gf/25 mm.
10 . The bendable display device of claim 1 , wherein the first adhesive layer has a thickness in a range of 1 μm to 50 μm.
11 . The bendable display device of claim 1 , wherein the first adhesive layer has a thickness in a range of 20 μm to 30 μm.