Anti-reflective film, polarizing plate, and display apparatus
The present invention relates to anti-reflective films including: a light-transmitting substrate; a hard coating layer; and a low refractive layer, wherein the low refractive layer includes a first region including a binder resin and high refractive inorganic nanoparticles and a second region including a binder resin and low refractive inorganic nanoparticles, and when polarization ellipticity measured by ellipsometry is fitted to a Cauchy model for each of the first region and the second region, predetermined requirements are fulfilled.
1. An anti-reflective film with a mean reflectance of 0.6% or less in the visible light wavelength region of 380 nm to 780 nm comprising:
a light transmitting substrate;
a hard coating layer formed on the light transmitting substrate; and
a low refractive index layer formed on the hard coating layer,
wherein the low refractive index layer comprises a first region comprising a binder resin and high refractive index inorganic nanoparticles, and a second region comprising the binder resin and low refractive index inorganic nanoparticles,
wherein the low refractive index inorganic nanoparticles comprise low refractive index inorganic nanoparticles that are hollow, mesoporous, or a combination thereof, and a ratio of an average particle diameter of the high refractive index inorganic nanoparticles to an average particle diameter of the low refractive index inorganic nanoparticles is 0.008 to 0.55,
wherein the first region of the low refractive index layer is positioned in contact with an interface between the hard coating layer and the low refractive index layer, and the second region of the low refractive index layer is positioned on the opposite side of the first region relative to the interface,
wherein the first region and the second region have an interface comprising the high refractive index inorganic nanoparticles and the low refractive index inorganic nanoparticles,
wherein each of the first region and the second region of the low refractive index layer has polarization ellipticity measured by ellipsometry using a Cauchy model represented by Equation 1 below, in which a difference between an A value of the first region and an A value of the second region is at least 0.200, the A value of the second region is 1.0 to 1.40, each of B values of the first and second regions is 0 to 0.1, and each of C values of the first and second regions is 0 to 0.01,
wherein the first and second regions are optical regions that are distinguished from each other as determined by the polarization ellipticity measured by ellipsometry using the Cauchy model represented by Equation 1, and
wherein the second region of the low refractive layer has a refractive index of 1.45 or less at 550 nm, and the first region of the low refractive layer has a refractive index of at least 1.55 at 550 nm:
n
(
λ
)
=
A
+
B
λ
2
+
C
λ
4
[
Equation
1
]
wherein, in the Equation 1, n(λ) is a refractive index at a λ, wavelength, λ, is in a range of 300 nm to 1800 nm, and A, B, and C are Cauchy parameters.
2. The anti-reflective film according to claim 1 , wherein,
the A value of the first region is 1.50 to 2.00.
3. The anti-reflective film according to claim 1 , wherein
the anti-reflective film has reflectance of 0.4% or less in the visible light wavelength region of 380 nm to 780 nm.
4. The anti-reflective film according to claim 1 , wherein
the first region has a thickness of 20 nm to 300 nm, and
the second region has a thickness of 70 nm to 400 nm.
5. The anti-reflective film according to claim 1 , wherein
the high refractive index inorganic nanoparticles include one or more selected from the group consisting of titanium dioxide (TiO 2 ), diantimony trioxide (Sb 2 O 3 ), zirconium dioxide (ZrO 2 ), tin oxide (SnO2), magnesium oxide (MgO), zinc oxide (ZnO), barium titanate (BaTiO 3 ), aluminum oxide (Al 2 O 3 ), cerium oxide (CeO 2 ), zirconium titanate, and strontium titanate, and
the low refractive index inorganic nanoparticles include one or more selected from the group consisting of hollow silica and mesoporous silica.
6. The anti-reflective film according to claim 1 , wherein
the first region comprises 70 vol % or more of the high refractive index inorganic nanoparticles, and
the second region comprises 70 vol % or more of the low refractive index inorganic nanoparticles.
7. The anti-reflective film according to claim 1 , wherein
the binder resin in the first region and the second region comprises a crosslinked (co)polymer of a (co)polymer of photopolymerizable compounds and fluorine-containing compounds comprising photoreactive functional groups.
8. The anti-reflective film according to claim 1 , wherein
the second region of the low refractive layer has a refractive index of 1.0 to 1.45 at 550 nm, and
the first region of the low refractive layer has a refractive index of 1.55 to 2.50 at 550 nm.
9. The anti-reflective film according to claim 1 , wherein
the hard coating layer comprises a binder resin comprising a photocurable resin and organic or inorganic fine particles dispersed in the binder resin.
10. The anti-reflective film according to claim 9 , wherein
the organic fine particles have a particle diameter of 1 to 10 μm, and the inorganic fine particles have a particle diameter of 1 nm to 500 nm.
11. The anti-reflective film according to claim 1 , wherein
the light-transmitting substrate includes one or more selected from the group consisting of a cycloolefin polymer film, a poly(meth)acrylate-based film, a polycarbonate film, a triacetyl cellulose (TAC) film, a polynorbornene film, and a polyester film.
12. The anti-reflective film according to claim 1 , wherein
the light-transmitting substrate is a polyethylene terephthalate film having a thickness direction retardation (Rth) of at least 3000 nm at a wavelength of 400 nm to 800 nm.
13. A polarizing film comprising the anti-reflective film of claim 1 .
14. A display apparatus comprising the anti-reflective film of claim 1 .
15. The anti-reflective film according to claim 1 , wherein
the low refractive index inorganic nanoparticles further comprise magnesium fluoride (MgF 2 ).
16. An anti-reflective film with a mean reflectance of 0.6% or less in the visible light wavelength region of 380 nm to 780 nm comprising:
a light transmitting substrate;
a hard coating layer formed on the light transmitting substrate; and
a low refractive index layer formed on the hard coating layer,
wherein the low refractive index layer comprises a first region comprising a binder resin and high refractive index inorganic-nanoparticles, and a second region comprising the binder resin and low refractive index inorganic nanoparticles,
wherein the low refractive index inorganic nanoparticles comprise low refractive index inorganic nanoparticles that are hollow, mesoporous, or a combination thereof, and a ratio of an average particle diameter of the high refractive index inorganic nanoparticles to an average particle diameter of the low refractive index inorganic nanoparticles is 0.008 to 0.55,
wherein the first region of the low refractive index layer is positioned in contact with an interface between the hard coating layer and the low refractive index layer, and the second region of the low refractive index layer is positioned on the opposite side of the first region relative to the interface,
wherein the first region and the second region have an interface comprising the high refractive index inorganic nanoparticles and the low refractive index inorganic nanoparticles, and
wherein each of the first region and the second region of the low refractive index layer has polarization ellipticity measured by ellipsometry using a Cauchy model represented by Equation 1 below, in which a difference between an A value of the first region and an A value of the second region is at least 0.200, the A value of the first region is 1.50 to 2.00, each of B values of the first and second regions is 0 to 0.10, and each of C values of the first and second regions is 0 to 0.01, and
wherein the first and second regions are optical regions that are distinguished from each other as determined by the polarization ellipticity measured by ellipsometry using the Cauchy model represented by Equation 1, and
wherein the second region of the low refractive layer has a refractive index of 1.45 or less at 550 nm, and the first region of the low refractive layer has a refractive index of at least 1.55 at 550 nm:
n
(
λ
)
=
A
+
B
λ
2
+
C
λ
4
[
Equation
1
]
wherein, in the Equation 1, n(κ) is a refractive index at a λ, wavelength, λ, is in a range of 300 nm to 1800 nm, and A, B, and C are Cauchy parameters.
17. The anti-reflective film according to claim 16 , wherein
the A value of the second region is 1.0 to 1.40.
18. The anti-reflective film according to claim 16 , wherein
the anti-reflective film has reflectance of 0.4% or less in the visible light wavelength region of 380 nm to 780 nm.
19. The anti-reflective film according to claim 16 , wherein
the first region has a thickness of 20 nm to 300 nm, and
the second region has a thickness of 70 nm to 400 nm.
20. The anti-reflective film according to claim 16 , wherein
the low refractive index inorganic nanoparticles further comprise magnesium fluoride (MgF 2 ).