Polarizing plate and optical display device comprising same
Provided are a polarizing plate and an optical display device comprising same, the polarizing plate comprising a polarizer and a protective film formed on at least one surface of the polarizer, wherein the polarizer has a depolarization region on at least a part thereof, and the polarizer has a crystallization degree of formula 1 of about 60% or greater.
1 . A polarizing plate comprising: a polarizer; and a protective film formed on at least one surface of the polarizer,
wherein the polarizer is formed with a depolarization region on at least part thereof and has a crystallinity ratio of about 60% or more, as calculated by Equation 1:
Crystallinity ratio= DC 2 /DC 1×100, [Equation 1]
where DC 1 is a crystallinity of a region of the polarizer other than the depolarization region, and
DC 2 is a crystallinity of the depolarization region of the polarizer.
2 . The polarizing plate according to claim 1 , wherein the depolarization region has a total remaining-iodine content of about 0.1 wt % to about 1.5 wt %.
3 . An optical display device comprising the polarizing plate according to claim 2 .
4 . The polarizing plate according to claim 1 , wherein the depolarization region occupies an area ratio of about 20% or less in the polarizer.
5 . An optical display device comprising the polarizing plate according to claim 3 .
6 . The polarizing plate according to claim 1 , wherein the depolarization region has a surface roughness (Ra) of about 3.0 nm or less.
7 . An optical display device comprising the polarizing plate according to claim 6 .
8 . The polarizing plate according to claim 1 , wherein the depolarization region has a curved or flat outer surface not formed with irregular roughness.
9 . An optical display device comprising the polarizing plate according to claim 8 .
10 . The polarizing plate according to claim 1 , wherein the polarizer further comprises a polarization region excluding the depolarization region and the polarizing plate has a shrinkage rate of about 5% or less, as calculated by Equation 2:
Shrinkage rate=| L 2− L 1|/ L 1×100, [Equation 2]
where L 1 is an initial length of the polarizer or the polarizing plate in an absorption axis direction thereof, and
L 2 is a length of the polarizer or the polarizing plate in the absorption axis direction thereof, after the polarizer or the polarizing plate is left at 85° C. for 120 hours.
11 . The polarizing plate according to claim 10 , wherein the depolarization region and the polarization region are consecutive to each other.
12 . An optical display device comprising the polarizing plate according to claim 11 .
13 . An optical display device comprising the polarizing plate according to claim 10 .
14 . An optical display device comprising the polarizing plate according to claim 1 .