Optical laminate comprising an optical functional layer and a porous layer
The present disclosure relates to an optical laminate or a reddening-resistant layer. The present disclosure can provide 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; and
a porous layer formed on at least one side of the optical functional layer,
wherein the porous layer comprises a surface having a surface area ratio of 0.02 or more as measured by an atomic force microscope,
wherein the porous layer comprises a binder and hollow particles,
wherein the binder comprises a polymer derived from a polyfunctional acrylate having 2 to 10 polymerizable functional groups,
wherein the hollow particles have a D10 particle diameter in a range from 25 to 50 nm, a D50 particle diameter in a range from 50 to 100 nm and a D90 particle diameter in a range from 100 nm to 200 nm in a weight cumulative curve of particle size distribution.
2. The optical laminate according to claim 1 , wherein an absolute value of a change in an amount of color coordinate a* of CIE L*a*b* according to Equation 1 is 2 or less:
Δ a*=a* a −a* i [Equation 1]
wherein Δa* is the change in the amount of the color coordinate a*, a* a is a color coordinate a* of the optical laminate after maintaining the optical laminate at 105° C. for 250 hours under a state where both top and bottom surfaces of the optical laminate come in contact with glass substrates and a* i is a color coordinate a* of the optical laminate before maintaining the optical laminate at 105° C. for 250 hours.
3. The optical laminate according to claim 1 , wherein an absolute value of a change in an amount of transmittance according to Equation 2 is 5 or less:
Δ Ts=T a −T i [Equation 2]
wherein ΔTs is the change in the amount of the transmittance, T a is a transmittance of the optical laminate after maintaining the optical laminate at 105° C. for 250 hours under a state where both top and bottom surfaces of the optical laminate come in contact with glass substrates, and T i is a transmittance of the optical laminate before maintaining the optical laminate at 105° C. for 250 hours.
4. The optical laminate according to claim 1 , wherein the optical functional layer is an iodine-based polarizing layer.
5. The optical laminate according to claim 1 , wherein the porous layer has reflectance of 2% or more with respect to light having a wavelength of 800 nm to 1300 nm.
6. The optical laminate according to claim 1 , wherein the porous layer exhibits at least one peak within a scattering vector range of 0.06 to 0.209 nm −1 in a log value graph of scattering intensity of small angle X-ray scattering.
7. The optical laminate according to claim 1 , wherein an A value satisfying Equation 6 of the porous layer is 1.5 or less, a B value satisfying Equation 6 of the porous layer is from 0 to 0.01 and a C value satisfying Equation 6 of the porous layer is from 0 to 0.001:
n
(
λ
)
=
A
+
B
λ
2
+
C
λ
4
[
Equation
6
]
wherein n(λ) is the refractive index of the porous layer at a wavelength of λ, and λ is any one wavelength in a range of 300 to 1800 nm.
8. The optical laminate according to claim 1 , wherein the porous layer does not comprise solid particles.
9. The optical laminate according to claim 1 , wherein the porous layer has a thickness of 200 nm or more.
10. The optical laminate according to claim 1 , wherein the porous layer does not form a surface of an outermost layer in the optical laminate.
11. The optical laminate according to claim 1 , wherein the distance between the porous layer and the optical functional layer is 90 μm or less.