Optical Material

Abstract

An acrylic thermoplastic resin composition includes a first acrylic resin having a first structural unit represented by the following formula (1) and a second structural unit represented by the following formula (2), and a second acrylic resin having the first structural unit represented by the following formula (1) and a third structural unit represented by the following formula (3), in which a total content of the first unit is 50 to 95 mass % and a total content of the second structural unit and the third structural unit is 5 to 50 mass % based on a total amount of the first acrylic resin and the second acrylic resin:

1 . An optic material comprising:
 a first acrylic resin having a first structural unit represented by the following formula (1) and a second structural unit represented by the following formula (2); and   a second acrylic resin having the first structural unit represented by the following formula (1) and a third structural unit represented by the following formula (3),   wherein, when a total mass of the first structural unit, the second structural unit, and the third structural unit is 100 mass %, the first structural unit is included at 75-82 mass %, the second structural unit is included at 0.2-20.0 mass %, and the third structural unit is included at 4.0-19.8 mass %,   wherein, when shaped into a uniaxially-stretched film, a slope K in the following linear relational equation (a) by at least squares approximation satisfies the following equation (b):
   Δ n=K×S+C   (a)
 
   | K|≤ 0.30×10 −5   (b)
 
   wherein a birefringence in terms of a thickness of 100 μm of the uniaxially-stretched film is defined as Δn, a stretch ratio is defined as S, and C is a constant number and represents birefringence when not being stretched,   
       
         
           
           
               
               
           
         
         wherein R 1  represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aryl group having 6 to 14 carbon atoms with at least one substituent selected from the following Group A: 
         Group A: a halogen atom, a hydroxyl group, a nitro group, an alkoxy group having 1 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms; 
       
       
         
           
           
               
               
           
         
         wherein R 2  represents an arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aryl group having 6 to 14 carbon atoms with at least one substituent selected from the following Group B, and R 3  and R 4  each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms: 
         Group B: a halogen atom, a hydroxyl group, a nitro group, an alkoxy group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms, and an arylalkyl group having 7 to 14 carbon atoms; 
       
       
         
           
           
               
               
           
         
         wherein R 5  represents a hydrogen atom, a cycloalkyl group having 3 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms with at least one substituent selected from the following Group C, and R 6  and R 7  each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms: 
         Group C: a halogen atom, a hydroxyl group, a nitro group and an alkoxy group having 1 to 12 carbon atoms. 
       
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The optical material according to  claim 1 , wherein the R 1  is a methyl group, a cyclohexyl group, a phenyl group or a benzyl group, the R 2  is a phenyl group or a phenyl group with at least one substituent selected from the Group B, and the R 5  is a cyclohexyl group. 
     
     
         6 . The optical material according to  claim 1 , wherein the first acrylic resin has a weight average molecular weight Mw of 3000 to 1000000 and a ratio Mw/Mn of the weight average molecular weight Mw to a number average molecular weight Mn of 1 to 10 in terms of polymethyl methacrylate, which are measured by a GPC measuring method. 
     
     
         7 . The optical material according to  claim 1 , wherein the second acrylic resin has a weight average molecular weight Mw of 3000 to 1000000 and a ratio Mw/Mn of the weight average molecular weight Mw to a number average molecular weight Mn of 1 to 10 in terms of polymethyl methacrylate, which are measured by a GPC measuring method. 
     
     
         8 - 10 . (canceled) 
     
     
         11 . The optical material according to  claim 1 , wherein an absolute value of retardation Rth in a thickness direction is 11 nm or less in terms of a thickness of 100 μm, when shaped into a film. 
     
     
         12 . The optical material according to  claim 1 , wherein a glass-transition temperature Tg is 120° C. or more. 
     
     
         13 . The optical material according to  claim 1 , wherein a total light transmittance is 85% or more in terms of a thickness of 100 μm, when shaped into a film. 
     
     
         14 . A shaped article comprising the optical material according to  claim 1 . 
     
     
         15 . A film-like or sheet-like shaped article comprising the optical material according to  claim 1 . 
     
     
         16 . A film-like or sheet-like shaped article prepared by stretching at least in a uniaxial direction a resin sheet comprising the optical material according  claim 1  and shaped by extrusion. 
     
     
         17 . A film-like or sheet-like shaped article prepared by stretching at least in a uniaxial direction a resin sheet comprising the optical material according to  claim 1  and shaped by solution casting. 
     
     
         18 . A polarizing plate protection film comprising the optical material according to  claim 1 . 
     
     
         19 . A retardation film comprising the optical material according to  claim 1 . 
     
     
         20 . A retardation plate comprising the optical material according to  claim 1 . 
     
     
         21 . A transparent plastic substrate comprising the optical material according to  claim 1 . 
     
     
         22 . A lens comprising the optical material according to  claim 1 . 
     
     
         23 . The optical material according to  claim 1 , wherein an absolute value of retardation Re in an in-plane direction is 11 nm or less in terms of a thickness of 100 μm, when shaped into a film. 
     
     
         24 . The optical material according to  claim 1 , wherein an absolute value of a photoelastic coefficient is 3.0×10 −12  Pa −1  or less.