POLARIZING PLATE AND OPTICAL DISPLAY APPARATUS
A polarizing plate and an optical display apparatus including the same are disclosed. A polarizing plate includes: a polarizer; and a protective layer on at least one surface of the polarizer, and the polarizer includes a polyvinyl alcohol based film containing a dichroic material and contains a zinc cation and a sodium cation, and a ratio of the sodium cation to the zinc cation is in a range from 0.1 to 0.96, and a total content of the zinc cation and the sodium cation is in a range from 500 ppm to 1,500 ppm.
1 . A polarizing plate comprising:
a polarizer; and
a protective layer on at least one surface of the polarizer,
wherein the polarizer comprises a polyvinyl alcohol based film containing a dichroic material and contains a zinc cation and a sodium cation, and
wherein a ratio of the sodium cation to the zinc cation is in a range from 0.1 to 0.96, and a total content of the zinc cation and the sodium cation is in a range from 500 ppm to 1,500 ppm.
2 . The polarizing plate as claimed in claim 1 , wherein a content of the sodium cation in the polarizer is in a range from 100 ppm to 1,000 ppm, and a content of the zinc cation in the polarizer is in a range from 200 ppm to less than 1,500 ppm.
3 . The polarizing plate as claimed in claim 1 , wherein the sodium cation and the zinc cation are present in a total amount of 8% or more based on a total content of all metal cations in the polarizer on a ppm basis.
4 . The polarizing plate as claimed in claim 1 , wherein the sodium cation is derived from sodium sulfate (Na 2 SO 4 ), and the zinc cation is derived from zinc sulfate (ZnSO 4 ).
5 . The polarizing plate as claimed in claim 1 , wherein the polarizer further contains a potassium cation.
6 . The polarizing plate as claimed in claim 5 , wherein a ratio of the sodium cation to the potassium cation is in a range from 0.02 to 0.15.
7 . The polarizing plate as claimed in claim 5 , wherein a total content of the potassium cation and the sodium cation is in a range from 3,000 to 10,000 ppm.
8 . The polarizing plate as claimed in claim 5 , wherein a ratio of a sum of the sodium cation and the zinc cation to the potassium cation is in a range from 0.1 to 0.2.
9 . The polarizing plate as claimed in claim 5 , wherein the sodium cation, the zinc cation, and the potassium cation are present in a total amount of 90% based on a total content of all metal cations in the polarizer on a ppm basis.
10 . The polarizing plate as claimed in claim 5 , wherein the polarizer further contains a boron cation.
11 . The polarizing plate as claimed in claim 1 , wherein the polyvinyl alcohol based film contains both a hydrophilic functional group and a hydrophobic functional group.
12 . The polarizing plate as claimed in claim 1 , wherein the protective layer is on an outermost side of the polarizing plate.
13 . The polarizing plate as claimed in claim 12 , wherein the protective layer is formed of a composition comprising more than 95 wt % of an organic component.
14 . The polarizing plate as claimed in claim 13 , wherein the organic component comprises at least one selected from among a resin, an oligomer, and a monomer.
15 . An optical display apparatus comprising the polarizing plate as claimed in claim 1 .