Polarizing plate and display device comprising same
Provided are a polarizing plate including a polarizing film and protective films provided on both sides of the polarizing film and a display device including the same.
1. A polarizing plate, comprising:
a polarizing film; a first protective film provided on one side of the polarizing film; and a second protective film provided on the other side of the polarizing film,
wherein a contractive force in at least one direction of an absorption-axial direction and a transmission-axial direction of the first protective film and the second protective film is 13 kgf or less per width of 1 mm,
wherein each of the first protective film and the second protective film includes a cycloolefin polymer(COP)-based film,
wherein a contractive force in an absorption-axial direction of the polarizing film is more than 0 kgf to 40 kgf or less per width of 1 mm,
wherein a thickness of the polarizing film is in a range of 5 μm to 30 μm, a thickness of the first protective film is more than 0 μm and less than or equal to 23 μm, and a thickness of the second protective film is more than 0 μm and less than or equal to 40 μm, and
wherein the contractive force is measured by the following method:
1) in an environment of a room temperature (25° C.) and room humidity (50%), a sample is cut with a width of 10 mm and a length of 150 mm and then installed in a length direction on a universal tester, and any one of both fixed ends is pulled,
2) while the sample is forcibly stretched, a percentage strain and a load applied to the sample are simultaneously measured to obtain a percentage strain-load graph, and
3) in the percentage strain-load graph, the contractive force is calculated by the greatest slope among tangential slopes.
2. The polarizing plate of claim 1 , wherein the polarizing film is a polyvinylalcohol-based polarizing film.
3. The polarizing plate of claim 1 , wherein at least one of the first protective film and the second protective film includes a cycloolefin polymer (COP)-based film of which a contractive force is 10 kgf or less per width of 1 mm.
4. The polarizing plate of claim 1 , further comprising:
a pressure-sensitive adhesive layer positioned on the first protective film,
wherein the second protective film includes one or more additives selected from a UV absorber, an anti-blocking agent, a lubricant, an antistatic agent, and a stabilizer.
5. The polarizing plate of claim 1 , wherein one or more layers selected from an anti-reflection layer, a low-reflection coating layer, a UV absorbing layer, a brightness enhancing layer, an antistatic coating layer, an antiglare layer, a liquid crystal coating layer, and a hard coat layer are additionally included on at least one of the first protective film and the second protective film.
6. A display device including the polarizing plate according to claim 1 .
7. A liquid crystal display including the polarizing plate according to claim 1 .