Polarizing plate and image display device comprising the same
The present invention provides a polarizing plate comprising a substrate, a polarizing coating layer formed on one side of the substrate, a first adhesive layer formed on the polarizing coating layer, a first retardation coating layer formed on the first adhesive layer, a second adhesive layer formed on the first retardation coating layer, a second retardation coating layer formed on the second adhesive layer, and a soft layer formed on the second retardation coating layer, wherein, the soft layer has an amended toughness of 1,000 to 40,000 MPa·%. The polarizing plate according to the present invention has excellent bending resistance and thus can be effectively used for a flexible display.
1. A polarizing plate comprising a substrate, a polarizing coating layer formed on one side of the substrate, a first adhesive layer formed on the layer formed on the first adhesive layer, a second adhesive layer formed on the first retardation coating layer, a second retardation coating layer formed on the second adhesive layer and a soft layer formed on the second retardation coating layer, wherein the soft layer has an amended toughness defined by the following Equation 1 of 1,000 to 40,000 MPa·%:
Amended toughness=Maximum stress×maximum strain [Equation 1]
wherein,
the maximum stress represents the stress at the fracture point in a stress-strain curve, and
the maximum strain represents the strain at the fracture point in the stress-strain curve.
2. The polarizing plate of claim 1 , wherein the first retardation coating layer is a λ/4 layer, and the second retardation coating layer is a positive C layer.
3. An image display device comprising the polarizing plate of claim 2 .
4. The polarizing plate of claim 1 , wherein the first retardation coating layer is a positive C layer, and the second retardation coating layer is a λ/4 layer.
5. An image display device comprising the polarizing plate of claim 4 .
6. The polarizing plate of claim 1 , wherein the first adhesive layer or the second adhesive layer is a pressure sensitive adhesive layer formed by a pressure sensitive adhesive or an adhesive layer formed by an adhesive.
7. An image display device comprising the polarizing plate of claim 6 .
8. The polarizing plate of claim 1 , wherein the soft layer is a coating layer.
9. An image display device comprising the polarizing plate of claim 8 .
10. The polarizing plate of claim 8 , wherein the soft layer is formed from a composition for forming a soft layer including a urethane acrylate oligomer, a photoinitiator and a solvent.
11. An image display device comprising the polarizing plate of claim 10 .
12. The polarizing plate of claim 1 , wherein the soft layer is a substrate film.
13. An image display device comprising the polarizing plate of claim 12 .
14. The polarizing plate of claim 1 , further including a polarizing coating protective layer between the polarizing coating layer and the first adhesive layer.
15. An image display device comprising the polarizing plate of claim 14 .
16. An image display device comprising the polarizing plate of claim 1 .
17. A flexible display comprising the polarizing plate of claim 1 .