Polycarbonate resin and transparent film formed therefrom

Abstract

The polycarbonate resin of the invention includes a first structural unit derived from a dihydroxy compound represented by a general formula (1), a second structural unit derived from a dihydroxy compound represented by a general formula (2), and a third structural unit derived from at least one dihydroxy compound selected from the group consisting of a dihydroxy compound represented by a general formula (3), a dihydroxy compound represented by a general formula (4), a dihydroxy compound represented by a general formula (5), and a dihydroxy compound represented by a general formula (6), and in which the first structural unit derived from a dihydroxy compound represented by the general formula (1) accounts for 18% by mole or more of the polycarbonate resin. The above general formulae (1) to (6) are described in the specification of the present application.

1 - 42 . (canceled) 
     
     
         43 . A polycarbonate resin comprising:
 a first structural unit derived from a dihydroxy compound represented by a general formula (1);   a second structural unit derived from a dihydroxy compound represented by a general formula (2); and   a third structural unit derived from at least one dihydroxy compound represented by a general formula (6),   wherein the dihydroxy compound represented by the general formula (1) is 9,9-[4-(2-hydroxyethoxy)phenyl]fluorene,   wherein the first structural unit accounts for 18% by mole or more of the polycarbonate resin, and   wherein the polycarbonate resin has a reduced viscosity of 0.30 dL/g or higher;   
       
         
           
           
               
               
           
         
       
       wherein the general formula (1), R 1  to R 4  each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6-20 carbon atoms, or a substituted or unsubstituted aryl group having 6-20 carbon atoms, X represents a substituted or unsubstituted alkylene group having 2-10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6-20 carbon atoms, or a substituted or unsubstituted arylene group having 6-20 carbon atoms, and m and n each independently are an integer of 0-5; 
       
         
           
           
               
               
           
         
       
       wherein the general formula (6), R 11  represents either an alkyl group having 2-20 carbon atoms or the group represented by a formula (7); 
       
         
           
           
               
               
           
         
       
     
     
         44 . The polycarbonate resin according to  claim 43 , wherein the polycarbonate resin has a reduced viscosity of 0.35 dL/g or higher. 
     
     
         45 . The polycarbonate resin according to  claim 43 , wherein the third structural unit accounts for 25% by mole or more of the polycarbonate resin. 
     
     
         46 . The polycarbonate resin according to  claim 43 , wherein the polycarbonate resin has a birefringence (Δn2) of 0.001 or higher in the state of having been stretched in a free-end stretch ratio of 2.0 under the conditions of (glass-transition temperature of the polycarbonate resin)+5° C. 
     
     
         47 . A transparent film having a birefringence of more than 0.001, comprising:
 a polycarbonate resin which comprises:   a first structural unit derived from a dihydroxy compound represented by a general formula (1);   a second structural unit derived from a dihydroxy compound represented by a general formula (2); and   a third structural unit derived from at least one dihydroxy compound represented by a general formula (6),   wherein the dihydroxy compound represented by the general formula (1) is 9,9-[4-(2-hydroxyethoxy)phenyl]fluorene,   wherein the first structural unit accounts for 18% by mole or more of the polycarbonate resin, and   wherein the polycarbonate resin has a reduced viscosity of 0.30 dL/g or higher   
       
         
           
           
               
               
           
         
       
       wherein the general formula (1), R 1  to R 4  each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6-20 carbon atoms, or a substituted or unsubstituted aryl group having 6-20 carbon atoms, X represents a substituted or unsubstituted alkylene group having 2-10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6-20 carbon atoms, or a substituted or unsubstituted arylene group having 6-20 carbon atoms, and m and n each independently are an integer of 0-5; 
       
         
           
           
               
               
           
         
       
       wherein the general formula (6), R 11  represents either an alkyl group having 2-20 carbon atoms or the group represented by a formula (7); 
       
         
           
           
               
               
           
         
       
     
     
         48 . The transparent film according to  claim 47 , wherein the transparent film has been stretched at least in one direction. 
     
     
         49 . The transparent film according to  claim 47 , wherein the transparent film has a refractive index as measured with sodium D-line (589 nm) in the range of 1.57 to 1.62. 
     
     
         50 . The transparent film according to  claim 47 , wherein the transparent film satisfies an expression (5).
   0.5 ≦R 450 /R 550≦1.0  (5)
   
       wherein the equation (5), R450 represents a retardation measured at a wavelength of 450 nm and R550 represents a retardation measured at a wavelength of 550 nm. 
     
     
         51 . The transparent film according to  claim 47 , wherein the transparent film has a thickness of 80 μm or less. 
     
     
         52 . The transparent film according to  claim 47 , wherein the transparent film satisfies one of expressions (6) to (8).
     nx>ny=nz   (6)
       nx>ny>nz   (7)
       nx>nz>ny   (8)
   
       wherein nx and ny represent refractive indexes in two in-plane directions, nz represents a refractive index in a thickness-direction of the transparent film. 
     
     
         53 . The transparent film according to  claim 47 , wherein the transparent film satisfies expressions (9) and (10);
     NZ =( nx−nz )/( nx−ny )=0.2 to 8  (9)
     Δ nd =( nx−ny )· d= 30 to 400  nm   (10)
   
       wherein nx and ny represent refractive indexes in two in-plane directions, nz represents a refractive index in a thickness-direction, and d represents a thickness of the transparent film. 
     
     
         54 . The transparent film according to  claim 47 , wherein the transparent film has a water absorption higher than 1.0% by weight. 
     
     
         55 . The transparent film according to  claim 47 , wherein the transparent film has a photoelastic coefficient of 40×10 −12  Pa −1  or less. 
     
     
         56 . A polarizing plate comprising the transparent film according to  claim 47  and a polarizer thereon.