Reddening-resistant layer
The present application relates to an optical laminate or a reddening-resistant layer. The present application 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. A reddening-resistant layer that is a void-containing layer or that comprises the void-containing layer,
wherein the void-containing layer has reflectance of 2% or more with respect to light having a wavelength of from 800 nm to 1,300 nm,
wherein the void-containing 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, and
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 95 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 reddening-resistant layer according to claim 1 , wherein a diameter of voids in the void-containing layer is from 0.5 nm to 100 nm.
3. The reddening-resistant layer according to claim 1 , wherein the void-containing layer satisfies Equation 4:
H L ≤0.9× H P [Equation 4]
wherein H L is a thermal diffusivity of a laminate of a polymer film and the reddening-resistant layer formed on one side of the polymer film, and H P is the thermal diffusivity of the polymer film.
4. The reddening-resistant layer according to claim 1 , wherein the void-containing layer comprises a surface having a surface area ratio of 0.02 or more as measured by an atomic force microscope.
5. The reddening-resistant layer according to claim 1 , wherein the void-containing 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.
6. The reddening-resistant layer according to claim 1 , wherein an A value satisfying Equation 6 of the void-containing layer is 1.5 or less, a B value satisfying Equation 6 of the void-containing layer is from 0 to 0.01 and a C value satisfying Equation 6 of the void-containing 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 void-containing layer at a wavelength of λ, and λ is any one wavelength in a range of 300 to 1800 nm.
7. The reddening-resistant layer according to claim 1 , wherein the void-containing layer does not comprise solid particles.
8. The reddening-resistant layer according to claim 1 , wherein the void-containing layer has a thickness of 200 nm or more.
9. An optical laminate, comprising:
an optical functional layer; and
the reddening-resistant layer of claim 1 formed on at least one side of the optical functional layer.
10. A display device, comprising:
a cover glass and
an optical laminate attached to the cover glass,
wherein the optical laminate comprises an optical functional layer and the reddening-resistant layer of claim 1 formed on at least one side of the optical functional layer.
11. The optical laminate of claim 9 , wherein the reddening-resistant layer exists adjacent to an optical functional layer and the distance between the reddening-resistant layer and the optical functional layer is 90 μm or less.
12. The optical laminate of claim 11 , wherein the optical functional layer is an iodine-based polarizing layer.