Polarizing plate and display using the same

Abstract

A polarizing plate comprising a polarizing film having thereon a retardation film containing a plasticizer and a cellulose ester, wherein a free volume radius of the retardation film determined by positron annihilation lifetime spectroscopy is in the range of 0.250-0.310 nm.

1 . A polarizing plate comprising a polarizing film having thereon a retardation film containing a plasticizer and a cellulose ester,  
     wherein a free volume radius of the retardation film determined by positron annihilation lifetime spectroscopy is in the range of 0.250-0.310 nm.  
   
   
       2 . The polarizing plate of  claim 1 , wherein 
 a free volume parameter of the retardation film is in the range of 1.0-2.0.    
   
   
       3 . The polarizing plate of  claim 1 , wherein 
 the cellulose ester is an ester of mixed aliphatic carboxylic acids each having 2-22 carbon atoms.    
   
   
       4 . The polarizing plate of  claim 1 , wherein Ro and Rt defined by the following formulas satisfy the following conditions: 
 Ro is in the range of 30-300 nm; and    Rt is in the range of 70-400 nm, wherein        Ro =( nx−ny )× d      Rt =((( nx+ny )/2)− nz )× d      wherein Ro represents an in-plane retardation value; Rt represents an out-of-plane retardation value in a thickness direction; nx represents an in-plane refractive index in a slow axis direction; ny represents an in-plane refractive index in a fast axis direction; nz represents an out-of-plane refractive index in the thickness direction; and d represents a thickness (nm) of the retardation film.    
   
   
       5 . A display comprising a liquid crystal cell, a direct illumination backlight unit and the polarizing plate of  claim 1.