Liquid crystal composition

Abstract

A liquid crystal composition is provided containing a first liquid crystal compound represented by formula (1): and a second liquid crystal compound represented by formula (2): Also provided is a method for producing the liquid crystal composition having a desired wavelength dispersion characteristic.

1 . A liquid crystal compound comprising a first liquid crystal compound represented by formula (1) and a second liquid crystal compound represented by formula (2): 
       
         
           
           
               
               
           
         
       
       wherein Ar is a divalent aromatic group, and at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom may be contained in the aromatic group;
 G represents a divalent alicyclic hydrocarbon group, where a hydrogen atom contained in the alicyclic hydrocarbon group is optionally substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoro alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and —CH 2 — contained in the alicyclic hydrocarbon group is optionally substituted with —O—, —S— or —NH—; 
 B represents a single bond or a divalent linking group; 
 A represents a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, the hydrogen atom contained in the alicyclic hydrocarbon group and the aromatic hydrocarbon group is optionally substituted with an alkyl group having 1 to 4 carbon atoms optionally substituted with a halogen atom, an alkoxy group having 1 to 4 carbon atoms optionally substituted with a fluorine atom, a cyano group or a nitro group, —CH 2 — contained in the alicyclic hydrocarbon group is optionally substituted with —O—, —S—, or —NR 1 —, and —CH(−)-contained in the alicyclic hydrocarbon group is optionally substituted with —N(−)-; 
 R 1  represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; 
 k represents an integer of 0 to 3, where when k is an integer of 2 or more, a plurality of As and Bs may be the same or different from each other, 
 E represents an alkanediyl group having 1 to 17 carbon atoms, where the hydrogen atom contained in an alkanediyl group is optionally substituted with a halogen atom, and —CH 2 — contained in the alkanediyl group is optionally substituted with —O— or —CO—; and 
 P represents a polymerizable group. 
 
     
     
         2 . The liquid crystal composition according to  claim 1 , wherein G, A, B, E, P and k in the formula (1) are the same as G, A, B, E, P and k in the formula (2), respectively. 
     
     
         3 . The liquid crystal composition according to  claim 1 , wherein an optical film obtained by orienting the first liquid crystal compound exhibits a reverse wavelength dispersion characteristic. 
     
     
         4 . The liquid crystal composition according to  claim 1 , wherein an optical film obtained by orienting the second liquid crystal compound exhibits a positive wavelength dispersion characteristic. 
     
     
         5 . The liquid crystal composition according to  claim 1 , wherein the aromatic group in Ar has 10 to 30 n electrons. 
     
     
         6 . The liquid crystal composition according to  claim 1 , wherein a maximum absorption wavelength (λ max ) of the first liquid crystal compound is from 300 to 400 nm. 
     
     
         7 . The liquid crystal composition according to  claim 1 , wherein an optical film obtained by orienting the liquid crystal composition has a degree of wavelength dispersion Re(450 nm)/Re(550 nm) of 0.65 or more and less than 1. 
     
     
         8 . The liquid crystal composition according to  claim 1 , wherein Ar is an aromatic group having a heterocyclic ring. 
     
     
         9 . The liquid crystal composition according to  claim 8 , wherein the aromatic group having a heterocyclic ring is an aromatic group having a benzothiazole ring. 
     
     
         10 . The liquid crystal composition according to  claim 1 , wherein a content of the second liquid crystal compound in the liquid crystal composition is in a range of 0.1 to 70 parts by mass relative to 100 parts by mass of the first liquid crystal compound. 
     
     
         11 . An optical film comprising a polymer of the liquid crystal composition as defined in  claim 1 . 
     
     
         12 . The optical film according to  claim 11 , wherein a retardation value (Re(550)) of the optical film at a wavelength of 550 nm is from 113 to 163 nm. 
     
     
         13 . A circularly polarizing plate comprising the optical film as defined in  claim 11  and a polarizing film. 
     
     
         14 . An organic electro-luminescence (EL) display device comprising an organic electro-luminescence panel containing the circularly polarizing plate as defined in  claim 13 . 
     
     
         15 . A method for producing a liquid crystal composition comprising a first liquid crystal compound represented by formula (1): 
       
         
           
           
               
               
           
         
       
       and a second liquid crystal compound represented by formula (2): 
       
         
           
           
               
               
           
         
       
       the method comprising a step of allowing a first alcohol compound represented by formula (3):
   P-EB-A k OH  (3)
 
 
       and a dicarboxylic acid compound represented by formula (4): 
       
         
           
           
               
               
           
         
       
       to react with each other to thereby obtain a mixture containing a carboxylic acid compound represented by formula (5): 
       
         
           
           
               
               
           
         
       
       and the second liquid crystal compound. 
     
     
         16 . The method according to  claim 15 , comprising a step of allowing the mixture containing the carboxylic acid compound and the second liquid crystal compound to react with a second alcohol compound (6) represented by formula (6):
   HO—Ar—OH  (6)
   
       to thereby obtain a liquid crystal composition containing the first and second liquid crystal compounds. 
     
     
         17 . The method according to  claim 15 , wherein an amount of the dicarboxylic acid compound used is from 1 to 50 moles, relative to 1 mole of the first alcohol compound. 
     
     
         18 . The method according to  claim 15 , wherein a reaction of the first alcohol compound and the dicarboxylic acid compound, and/or a reaction of the mixture containing the carboxylic acid compound and the second liquid crystal compound with the second alcohol compound is/are conducted in the presence of a condensing agent.