Optical laminate

1. An optical laminate, comprising:

an optical functional layer; and

a reddening-resistant layer formed on at least one surface of the optical functional layer,

wherein the reddening-resistant layer is a void-containing layer or a laminate comprising the void-containing layer,

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, and

wherein an absolute value of a change in a 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 color coordinate a*, a* a is a color coordinate a* after maintaining the optical laminate at 105° C. for 250 hours, wherein top and bottom surfaces of the optical laminate are in contact with glass substrates, and a* i is an initial color coordinate a* before maintaining the optical laminate at 105° C. for 250 hours.

2. 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 transmittance, T a is a transmittance of the optical laminate after maintaining the optical laminate at 105° C. for 250 hours, where top and bottom surfaces of the optical laminate are in contact with glass substrates, and T i is an initial transmittance of the optical laminate before maintaining the optical laminate at 105° ° C. for 250 hours.

3. The optical laminate according to claim 1 , wherein the optical functional layer is a polarizing layer or a retardation layer.

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 reddening-resistant 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 a surface of the polymer film, and H p is a thermal diffusivity of the polymer film.

6. 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.

7. The optical laminate according to claim 1 , wherein the reddening-resistant layer has a reflectance of 2% or more for light having a wavelength of 800 nm to 1300 nm.

8. The optical laminate according to claim 1 , wherein a diameter of a void in the void-containing layer is from 0.5 nm to 100 nm.

9. The optical laminate according to claim 1 , 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.

10. The optical laminate according to claim 1 , wherein a volume fraction of voids in the void-containing layer is 0.1 or more.

11. The optical laminate according to claim 1 , wherein the void-containing layer comprises a binder and hollow particles.

12. The optical laminate according to claim 11 , wherein the binder comprises a polymer derived from a polyfunctional acrylate having 2 to 10 polymerizable functional groups.

13. The optical laminate according to claim 11 , 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.

14. The optical laminate according to claim 11 , wherein the void-containing layer does not comprise solid particles.

15. The optical laminate according to claim 1 , wherein the reddening-resistant layer has a thickness of 200 nm or more.

16. The optical laminate according to claim 1 , wherein the reddening-resistant layer does not form a surface of an outermost layer of the optical laminate.

17. The optical laminate according to claim 1 , further comprising an additional layer, wherein the reddening-resistant layer is positioned between the additional layer and the optical functional layer.

18. The optical laminate according to claim 17 , 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.

19. The optical laminate according to claim 1 , wherein the optical laminate has a surface reflectance of 2% or more for light having a wavelength of 380 nm to 780 nm.

20. 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.