Polarizing plate

Abstract

There is provided a polarizing plate, including: a polarizing layer having a thickness not greater than 20 μm; a first protective film stacked on one surface of the polarizing layer, with a first adhesive layer formed from an active energy ray curing adhesive being interposed; and a second protective film stacked on the other surface of the polarizing layer, with a second adhesive layer formed from a water-soluble adhesive being interposed. There are also provided a polarizing plate with a pressure sensitive adhesive layer, a substrate having a polarizing plate bonded thereto, a liquid crystal display device, and an organic electroluminescence display device, all of which include the polarizing plate. Preferably, at least one of the first protective film and the second protective film has a moisture permeability not higher than 1000 g/m 2 /24 hr.

1 . A polarizing plate assembly, comprising a polarizing plate and a transparent pressure sensitive adhesive layer,
 the polarizing plate including:   a polarizing layer having a thickness not greater than 20 μm;   a first protective film stacked on one surface of the polarizing layer, with a first adhesive layer formed from an active energy ray curing adhesive interposed therebetween; and   a second protective film stacked on the other surface of the polarizing layer, with a second adhesive layer formed from a water-soluble adhesive interposed therebetween, and   the transparent pressure sensitive adhesive layer being located on a side of the polarizing plate having the first protective film.   
     
     
         2 . The polarizing plate assembly according to  claim 1 , wherein
 at least one of the first protective film and the second protective film has a moisture permeability not higher than 1000 g/m 2 /24 hr.   
     
     
         3 . The polarizing plate assembly according to  claim 1 , wherein
 the second protective film has a moisture permeability of 10 to 1000 g/m 2 /24 hr.   
     
     
         4 . The polarizing plate assembly according to  claim 1 , wherein
 the polarizing layer is a stretched polyvinyl alcohol-based resin layer containing a dichroic colorant.   
     
     
         5 . The polarizing plate assembly according to  claim 1 , wherein
 the polarizing layer has a thickness not greater than 10 μm.   
     
     
         6 . The polarizing plate assembly according to  claim 1 , wherein
 the polarizing plate has a rectangular shape having a diagonal length of 3 to 32 cm.   
     
     
         7 . The polarizing plate assembly according to  claim 1 , further comprising
 a surface treatment layer stacked on a surface of the first protective film or the second protective film, the surface being a surface on an opposite side of the polarizing layer.   
     
     
         8 . The polarizing plate assembly according to  claim 7 , wherein
 the surface treatment layer is a hard coat layer, an antireflective layer or an electroconductive layer.   
     
     
         9 . The polarizing plate assembly according to  claim 1 , wherein
 the first protective film or the second protective film has a thickness not greater than 50 μm.   
     
     
         10 . The polarizing plate assembly according to  claim 1 , wherein
 a tensile elastic modulus at 80° C. of the first protective film or the second protective film is not lower than 1500 MPa.   
     
     
         11 . The polarizing plate assembly according to  claim 1 , wherein:
 the polarizing plate assembly is disposed at a viewing side of an image display element.   
     
     
         12 . A substrate having a polarizing plate bonded thereto, comprising:
 the polarizing plate assembly as recited in  claim 1 ; and   a substrate, wherein   the polarizing plate is bonded to a surface of the substrate on a side of the polarizing plate having the first protective film, with the transparent pressure sensitive adhesive layer being interposed therebetween.   
     
     
         13 . A liquid crystal display device, comprising:
 the polarizing plate assembly as recited in  claim 1 ; and   a liquid crystal cell including a substrate, wherein   the polarizing plate is bonded to a surface of the substrate on a side of the polarizing plate having the first protective film, with the transparent pressure sensitive adhesive layer being interposed therebetween, and   a resolution of a display screen is not lower than 300 dpi.   
     
     
         14 . The liquid crystal display device according to  claim 13 , wherein the liquid crystal cell is a normally black-type liquid crystal cell. 
     
     
         15 . An organic electroluminescence display device, comprising:
 the polarizing plate assembly as recited in  claim 1 ; and   an organic electroluminescence display element including a substrate, wherein   the polarizing plate is bonded to a surface of the substrate on a side of the polarizing plate having the first protective film, with the transparent pressure sensitive adhesive layer being interposed therebetween, and   the first protective film has an in-plane phase retardation value of 100 to 180 nm, and an angle of a slow axis of the first protective film with respect to an absorption axis of the polarizing layer is substantially 45° or substantially 135°.