Low refractive layer and anti-reflective film comprising the same (as amended)
The present invention relates to a low refractive layer and an anti-reflective film comprising the same. The low refractive layer can exhibit excellent optical properties such as a low reflectance and a high light transmittance, and excellent mechanical properties such as high wear resistance and scratch resistance at the same time. In particular, due to the excellent alkali resistance, the low refractive layer can maintain excellent physical properties even after alkali treatment. Therefore, when introducing a low refractive layer to the display device, it is expected that the production process can be simplified and further the production rate and the productivity can significantly increase.
1. A low refractive layer comprising a photo-cured product obtained by photo-curing a photocurable coating composition comprising:
a photopolymerizable compound,
a polysilsesquioxane,
a fluorine based compound,
an inorganic particle, and
a photopolymerization initiator,
wherein the polysilsesquioxane comprises a reactive group and a non-reactive group, the reactive group being selected from the group consisting of alcohol, amine, carboxylic acid, epoxide, imide, (meth)acrylate, nitrile, norbornene, olefin, polyethylene glycol, thiol and vinyl groups, the non-reactive group being selected from the group consisting of a straight chain or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 6 to 30 carbon atoms and an aryl group having 6 to 30 carbon atoms,
wherein the fluorine based compound has a fluorine content of 1-25 wt % and includes a photoreactive functional group and a —O—CF 2 CF 2 —O—CF 3 group,
wherein the photocurable coating composition comprises 20-80 wt % of the photopolymerizable compound based on the solid content of the photocurable coating composition, 0.5-25 parts by weight of the polysilsesquioxane per 100 parts by weight of the photopolymerizable compound, 1 to 75 parts by weight of the fluorine based compound per 100 parts by weight of the photopolymerizable compound, and 10-320 parts by weight of the inorganic particle per 100 parts by weight of the photopolymerizable compound, and
wherein the low refractive layer satisfies the following formula 1:
30%≥Δ S =[( S 0 −S 1 )/ S 0 ]×100 [Formula 1]
in the formula 1,
S 0 is the maximum load that scratches are not generated, when rubbing the surface of the low refractive layer while applying a load to a grade #0000 steel wool and reciprocating ten times at a speed of 24 rpm; and
S 1 is the maximum load that scratches are not generated, as measured in the same manner as a method of measuring S 0 as to the film prepared by immersing the low refractive layer for 2 minutes in 10 wt % sodium hydroxide aqueous solution heated to 30° C., washing the immersed layer with water, wiping moisture off, followed by immersing the low refractive layer for 30 seconds in 10 wt % sodium hydroxide aqueous solution heated to 55° C., and then washing the immersed layer with water and wiping moisture off.
2. The low refractive layer according to claim 1 , satisfying the following formula 2:
0.5≥Δ b*=|b* 1 −b* 0 | [Formula 2]
in the formula 2,
b* 0 is a b* value in a L*a*b* color coordinate system as defined by the International Commission on Illumination as to the low refractive layer; and
b* 1 is a b* value in a L*a*b* color coordinate system as measured in the same manner as a method for measuring b* 0 as to the film prepared by immersing the low refractive layer for 2 minutes in 10 wt % sodium hydroxide aqueous solution heated to 30° C., washing the immersed layer with water, wiping moisture off, followed by immersing the low refractive layer for 30 seconds in 10 wt % sodium hydroxide aqueous solution heated to 55° C., washing the immersed layer with water and wiping off moisture.
3. The low refractive layer according to claim 2 wherein the b* 0 value in the formula 2 is from 1 to −8.
4. The low refractive layer according to claim 1 wherein when measuring the reflectance of the low refractive layer from 380-780 nm of wavelength, the minimum reflectance occurs in the wavelength range of 480-680 nm.
5. The low refractive layer according to claim 1 wherein an average reflectance for light in the wavelength range of 380 to 780 nm is from 0.9 to 2.5%.
6. An anti-reflective film comprising a low refractive layer of claim 1 ; and a hard coating layer formed on one surface of the low refractive layer.