Polarizing plate having specified ratio of polarizing film shrinkage force to protective film shrinkage force
The present application relates to a polarizing plate having a polarizing film in which a light absorption axis is formed in one in-plane direction; a protective film formed on one side of the polarizing film; and a pressure-sensitive adhesive layer formed on the other side of the polarizing film, where the total thickness is 200 μm or less, and a ratio of (S Pro /S PVA ) of a shrinkage force (S PVA ) of the polarizing film in the in-plane direction parallel to the light absorption axis direction and a shrinkage force (S Pro ) of the protective film in the in-plane direction perpendicular to the light absorption axis direction is in a range of 0.1 to 5. The present application can provide a polarizing plate which does not cause cracks or the like while having a thin thickness, does not induce warping or twisting in itself and does not induce the above problems even when applied to a display device such as an LCD or OLED.
1. A polarizing plate comprising
a polarizing film in which a light absorption axis is formed in one in-plane direction;
a protective film formed on one side of the polarizing film;
and a pressure-sensitive adhesive layer formed on the other side of the polarizing film,
wherein the total thickness is 200 μm or less,
a ratio of (S Pro /S PVA ) of a shrinkage force (S PVA ) of the polarizing film in the in-plane direction parallel to the light absorption axis direction and a shrinkage force (S Pro ) of the protective film in the in-plane direction perpendicular to the light absorption axis direction is in a range of 0.1 to 5; and
a ratio (S/S Pro ) of the shrinkage force (S Pro ) of the protective film in the in-plane direction perpendicular to the light absorption axis direction of the polarizing film and the shrinkage force (S) of the protective film in the in-plane direction parallel to the light absorption axis direction of the polarizing film is in a range of 2 to 20.
2. The polarizing plate according to claim 1 , wherein the ratio (S/S Pro ) of the shrinkage force (S Pro ) of the protective film in the in-plane direction perpendicular to the light absorption axis direction of the polarizing film and the shrinkage force (S) of the protective film in the in-plane direction parallel to the light absorption axis direction of the polarizing film is in a range of 8 to 20.
3. The polarizing plate according to claim 1 , wherein the shrinkage force (S PVA ) of the polarizing film in the light absorption axis direction is in a range of 0.1 N to 15 N.
4. The polarizing plate according to claim 1 , wherein the protective film is a polyester film.
5. The polarizing plate according to claim 1 , wherein the thickness of the polarizing film is in a range of from 5 μm to 25 μm.
6. The polarizing plate according to claim 1 , wherein the thickness of the protective film is in a range of 20 82 m to 250 μm.
7. The polarizing plate according to claim 1 , wherein the thickness of the pressure-sensitive adhesive layer is in a range of 5 μm to 100 μm.
8. The polarizing plate according to claim 1 , further comprising an adhesive layer between the protective film and the polarizing film.
9. The polarizing plate according to claim 8 , wherein the adhesive layer has a thickness in a range of 2 μm to 4 μm.
10. The polarizing plate according to claim 1 , further comprising a cured resin layer between the polarizing film and the pressure-sensitive adhesive layer.
11. The polarizing plate according to claim 10 , wherein the cured resin layer has a thickness in a range of 4 μm to 10 μm.
12. A display device comprising the polarizing plate of claim 1 .
13. A polarizing plate comprising
a polarizing film in which a light absorption axis is formed in one in-plane direction;
a protective film formed on one side of the polarizing film; and
a pressure-sensitive adhesive layer formed on the other side of the polarizing film,
wherein the total thickness is 200 μm or less,
wherein a ratio of (S Pro /S PVA ) of a shrinkage force (S PVA ) of the polarizing film in the in-plane direction parallel to the light absorption axis direction and a shrinkage force (S Pro ) of the protective film in the in-plane direction perpendicular to the light absorption axis direction is in a range of 0.1 to 5, and
wherein the protective film has a ratio (S/S Pro ) of a shrinkage force (S Pro ) of the protective film in the in-plane direction perpendicular to the light absorption axis direction of the polarizing film and a shrinkage force (S) of the protective film in the in-plane direction parallel to the light absorption axis direction of the polarizing film is in a range of 2 to 20
wherein an A value in Equation 1 is in a range of 0.01 to 26 N·mm:
A=a ×( S PVA ×( T 1 +b )+ S Pro ×( T 2 +b )) [Equation 1]
wherein, in Equation 1, S PVA is the shrinkage force of the polarizing film in the light absorption axis direction, S Pro is a large shrinkage force among a shrinkage force of the protective film in the direction parallel to the light absorption axis direction of the polarizing film and a shrinkage force of the protective film in the direction perpendicular to the light absorption direction, T 1 is a distance (unit:mm) from the lowermost portion of the pressure-sensitive adhesive layer to the center of the polarizing film, T 2 is a distance (unit:mm) from the lowermost portion of the pressure-sensitive adhesive layer to the center of the protective film, a is a number within a range of 0.5 to 2, and b is a number within a range of 0.14 to 0.6.