Polarizing plate

Abstract

A primary object of the present invention is to provide a polarizing plate excellent in durability. A polarizing plate (100) according to an embodiment of the present invention includes: a polarizer (10); and a protective film (21 and 22) arranged on at least one side of the polarizer (10). The polarizing plate (100) has a dimensional change ratio of −0.2% or more in a transmission axis direction thereof when the polarizing plate (100) cut into a size measuring 100 mm by 100 mm is bonded to a glass plate with a pressure-sensitive adhesive and the following operation is repeated 100 times: the polarizing plate (100) bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes.

What is claimed is: 
     
         1 . A polarizing plate, comprising:
 a polarizer; and   a protective film arranged on at least one side of the polarizer,   wherein the polarizer has a thickness of 20 μm or less,   wherein the polarizing plate has a dimensional change ratio of −0.2% or more in a transmission axis direction thereof;   
       wherein the dimensional change ratio is measured by cutting the polarizing plate to 100 mm by 100 mm while bonded to a glass plate with a pressure-sensitive adhesive and an operation wherein the polarizing plate bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes, is repeated 100 times. 
     
     
         2 . The polarizing plate according to  claim 1 , wherein the polarizing plate has the dimensional change ratio of 0.1% or less. 
     
     
         3 . A polarizing plate, comprising:
 a polarizer; and   a protective film arranged on at least one side of the polarizer,   wherein the polarizer has a thickness of 20 μm or less,   wherein the polarizing plate has a dimensional change ratio of −0.2% or more in a transmission axis direction thereof;   
       wherein the dimensional change ratio is measured by cutting the polarizing plate to 100 mm by 100 mm while bonded to a glass plate with a pressure-sensitive adhesive and an operation wherein the polarizing plate bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes, is repeated 100 times, and
 the polarizing plate has one selected from the group consisting of a through-hole formed therein, a site having an outer edge forming a substantially V-shape that is convex inward in a surface direction, and the combination of the through-hole and the site. 
 
     
     
         4 . A polarizing plate, comprising:
 a polarizer; and   a protective film arranged on at least one side of the polarizer,   wherein the polarizing plate has a dimensional change ratio of −0.2% or more in a transmission axis direction thereof;   
       wherein the dimensional change ratio is measured by cutting the polarizing plate to 100 mm by 100 mm while bonded to a glass plate with a pressure-sensitive adhesive and an operation wherein the polarizing plate bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes, is repeated 100 times, and
 the polarizing plate has one selected from the group consisting of a through-hole formed therein, a site having an outer edge forming a substantially V-shape that is convex inward in a surface direction, and the combination of the through-hole and the site. 
 
     
     
         5 . The polarizing plate according to  claim 1 , further comprising a second protective film,
 wherein the second protective film is arranged on another side of the polarizer that is opposite to the protective film.   
     
     
         6 . The polarizing plate according to  claim 1 , wherein the polarizing plate has the dimensional change ratio of −0.1 to 0.1%. 
     
     
         7 . The polarizing plate according to  claim 1 , wherein the polarizing plate has a dimensional change ratio of −0.6 to 0% in an absorption axis direction,
 wherein the dimensional change ratio in an absorption axis direction is measured by cutting the polarizing plate to 100 mm by 100 mm while bonded to a glass plate with a pressure sensitive adhesive and an operation wherein the polarizing plate bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes, is repeated 100 times. 
 
     
     
         8 . The polarizing plate according to  claim 3 , further comprising a second protective film,
 wherein the second protective film is arranged on another side of the polarizer that is opposite to the protective film.   
     
     
         9 . The polarizing plate according to  claim 3 , wherein the polarizing plate has the dimensional change ratio of −0.1 to 0.1%. 
     
     
         10 . The polarizing plate according to  claim 3 , wherein the polarizing plate has a dimensional change ratio of −0.6 to 0% in an absorption axis direction,
 wherein the dimensional change ratio in an absorption axis direction is measured by cutting the polarizing plate to 100 mm by 100 mm while bonded to a glass plate with a pressure sensitive adhesive and an operation wherein the polarizing plate bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes, is repeated 100 times. 
 
     
     
         11 . The polarizing plate according to  claim 4 , further comprising a second protective film,
 wherein the second protective film is arranged on another side of the polarizer that is opposite to the protective film.   
     
     
         12 . The polarizing plate according to  claim 4 , wherein the polarizing plate has the dimensional change ratio of −0.1 to 0.1%. 
     
     
         13 . The polarizing plate according to  claim 4 , wherein the polarizing plate has a dimensional change ratio of −0.6 to 0% in an absorption axis direction,
 wherein the dimensional change ratio in an absorption axis direction is measured by cutting the polarizing plate to 100 mm by 100 mm while bonded to a glass plate with a pressure sensitive adhesive and an operation wherein the polarizing plate bonded to the glass plate is left to stand under an atmosphere at −40° C. for 30 minutes and then left to stand under an atmosphere at 85° C. for 30 minutes, is repeated 100 times.