Optical laminate
An optical laminate that does not cause a so-called reddening phenomenon even when driven or maintained under extremely harsh conditions (e.g., very high temperature conditions), or a reddening-resistant layer applied thereto.
1. An optical laminate, comprising:
an optical functional layer;
a reddening-resistant layer formed on at least one surface of the optical functional layer; and
an additional layer different from the optical functional layer and the reddening-resistant layer,
wherein the reddening-resistant layer is positioned between the additional layer and the optical functional layer.
2. The optical laminate according to claim 1 , wherein the optical functional layer is an iodine-based polarizing layer.
3. The optical laminate according to claim 1 , wherein the reddening-resistant layer comprises a surface having a surface area ratio of 0.02 or more as measured by an atomic force microscope.
4. The optical laminate according to claim 1 , wherein the reddening-resistant layer has reflectance of 2% or more for light having a wavelength of 800 nm to 1300 nm.
5. The optical laminate according to claim 1 , wherein the reddening-resistant layer is a void-containing layer or a layer comprising the void-containing layer.
6. The optical laminate according to claim 5 , wherein a diameter of a void in the void-containing layer is from 0.5 nm to 100 nm.
7. The optical laminate according to claim 5 , wherein the reddening-resistant layer exhibits at least one peak within a scattering vector range of 0.06 nm −1 to 0.209 nm −1 in a log value graph of scattering intensity of small angle X-ray scattering.
8. The optical laminate according to claim 5 , wherein a refractive index of the reddening-resistant layer satisfies Equation 6:
n
(
λ
)
=
A
+
B
λ
2
+
C
λ
4
.
[
Equation
6
]
wherein, n(λ) is the refractive index of the reddening-resistant layer at a wavelength of λ, λ is any one wavelength in a range of 300 nm to 1800 nm, A is 1.5 or less, B is from 0 to 0.01 and C is from 0 to 0.001.
9. The optical laminate according to claim 5 , wherein the void-containing layer comprises a binder and hollow particles.
10. The optical laminate according to claim 9 , wherein the binder comprises a polymer derived from a polyfunctional acrylate having 2 to 10 polymerizable functional groups.
11. The optical laminate according to claim 9 , wherein the hollow particles have a D10 particle diameter of 25 nm to 50 nm, a D50 particle diameter of 50 nm to 95 nm and a D90 particle diameter of 100 nm to 200 nm in a weight cumulative curve of particle size distribution.
12. The optical laminate according to claim 5 , wherein the void-containing layer does not comprise solid particles.
13. The optical laminate according to claim 1 , wherein the reddening-resistant layer has a thickness of 200 nm or more.
14. The optical laminate according to claim 1 , wherein the additional layer is a protective film, a pressure-sensitive adhesive layer, an adhesive layer, a hard coating layer, a retardation layer or a brightness enhancement layer.
15. The optical laminate according to claim 1 , wherein a distance between the reddening-resistant layer and the optical functional layer is 90 μm or less.