Azo Compound, Dye-Based Polarizing Film And Polarizing Plate

Abstract

The present invention relates to an azo compound represented by the following formula (1), [wherein, A represents a phenyl group which may have a substituent, R 1 to R 6 each independently represent a hydrogen atom, an alkyl group having a carbon atom number of 1 to 5, an alkoxy group having a carbon atom number of 1 to 5, a sulfo group, or an alkoxy group having a sulfo group and a carbon atom number of 1 to 5, and X represents an amino group which may have a substituent, a benzoylamino group which may have a substituent, a phenylamino group which may have a substituent, a phenylazo group which may have a substituent, or a naphthotriazole group which may have a substituent] or/and a salt thereof and to a polarizing film and a polarizing plate which contain it. The polarizing plate of the present invention using the above-described azo compound has a high polarization ratio and a high contrast, causes less color-leakage in a visible light region, is excellent in optical performance and durability, and can be widely used in liquid crystal displays such as liquid crystal projectors, and the like The formula (1)

1 . An azo compound represented by the following formula (1): 
       
         
           
           
               
               
           
         
       
       wherein, A represents a phenyl group which may have a substituent, R 1  to R 6  each independently represent a hydrogen atom, an alkyl group having a carbon atom number of 1 to 5, an alkoxy group having a carbon atom number of 1 to 5, or an alkoxy group having a sulfo group and a carbon atom number of 1 to 5, X represents a phenylamino group which may have a substituent, a phenylazo group which may have a substituent, or a naphthotriazole group which may have a substituent, or/and a salt thereof, wherein the phenylazo group which may have a substituent is represented by the following formula (5): 
       
         
           
           
               
               
           
         
       
       wherein, R 10  to R 12  each independently represent a hydrogen atom, a hydroxy group, an alkyl group having a carbon atom number of 1 to 5, an alkoxy group having a carbon atom number of 1 to 5, an amino group or a substituted amino group. 
     
     
         2 . The azo compound or/and a salt thereof according to  claim 1 , wherein X is a phenylamino group which may have a substituent, a phenylazo group which may have a substituent, or a naphthotriazole group which may have a substituent, and these substituents are an alkyl group having a carbon atom number of 1 to 5, an alkoxy group having a carbon atom number of 1 to 5, a hydroxy group, a carboxy group, a sulfo group, an amino group or a substituted amino group. 
     
     
         3 . The azo compound or/and a salt thereof according to  claim 1 , wherein X is a phenylamino group represented by the following formula (2): 
       
         
           
           
               
               
           
         
       
       wherein, R 7  and R 8  each independently represent a hydrogen atom, a methyl group, a methoxy group, a sulfo group, an amino group or a substituted amino group. 
     
     
         4 . The azo compound or/and a salt thereof according to  claim 1 , wherein X is a naphthotriazole group represented by the following formula (4): 
       
         
           
           
               
               
           
         
       
       wherein, m represents 1 or 2. 
     
     
         5 . The azo compound or/and a salt thereof according to  claim 1 , wherein at least one of substituents of A is a sulfo group or a carboxy group, and a substituent other than that is not present or is a sulfo group, an alkyl group having a carbon atom number of 1 to 5, an alkoxy group having a carbon atom number of 1 to 5, an alkoxy group having a sulfo group and a carbon atom number of 1 to 5, a carboxy group, a nitro group, an amino group or a substituted amino group. 
     
     
         6 . The azo compound or/and a salt thereof according to  claim 1 , wherein A is represented by the following formula (6): 
       
         
           
           
               
               
           
         
       
       wherein, one of R 13  and R 14  is a sulfo group and the other represents a hydrogen atom, a sulfo group, an alkyl group having a carbon atom number of 1 to 5, or an alkoxy group having a carbon atom number of 1 to 5. 
     
     
         7 . The azo compound or/and a salt thereof according to  claim 1 , wherein R 1  to R 6  are each independently a hydrogen atom, a methyl group, a methoxy group, a sulfo group, an alkoxy group having a sulfo group and a carbon atom number of 1 to 5. 
     
     
         8 . The azo compound or/and a salt thereof according to  claim 1 , which is represented by the following formula (7): 
       
         
           
           
               
               
           
         
       
       wherein, A, R 1  to R 6  and X have the same meanings as in the formula (1). 
     
     
         9 . The azo compound or/and a salt thereof according to  claim 1 , wherein A is a disulfo-substituted phenyl group, R 2 , R 4  and R 6  are each independently a methyl group or a methoxy group, R 1  and R 3  are each independently a hydrogen atom, a methyl group, a methoxy group or a sulfopropoxy group, R 5  is a methyl group or a methoxy group, and X is a unsubstituted phenylamino group, a phenylamino group having at least one group selected from the group consisting of a methoxy group, a sulfo group and an amino group as a substituent, or disulfo-substituted naphthotriazole. 
     
     
         10 . The azo compound or/and a salt thereof according to  claim 9 , Wherein R 2  and R 4  are methyl groups, R 6  is a methyl group or a methoxy group, and X is an unsubstituted phenylamino group or a methoxy-substituted phenylamino group. 
     
     
         11 . A dye-based polarizing film containing the azo compound or/and a salt thereof according to  claim 1  in a polarizing raw film. 
     
     
         12 . A dye-based polarizing film containing at least one kind of the azo compound or/and a salt thereof according to  claim 1  and at least one kind of other organic dyes in a polarizing raw film. 
     
     
         13 . A dye-based polarizing film containing at least two kinds of the azo compound or/and a salt thereof according to  claim 1  and at least one kind of other organic dyes in a polarizing raw film. 
     
     
         14 . A color dye-based polarizing film containing at least one kind of the azo compound or/and a salt thereof according to  claim 1  in a polarizing raw film. 
     
     
         15 . The dye-based polarizing film according to  claim 11 , wherein the polarizing raw film is a film comprising a polyvinyl alcohol resin, a vinyl alcohol copolymer resin or a modified polyvinyl alcohol resin. 
     
     
         16 . The dye-based polarizing film according to  claim 15 , wherein the polarizing raw film is a polyvinyl alcohol resin film. 
     
     
         17 . A dye-based polarizing plate with a transparent protective film being attached on at least one surface of the dye-based polarizing film according to  claim 11 . 
     
     
         18 . A liquid crystal display comprising the dye-based polarizing film according to  claim 11 . 
     
     
         19 . A liquid crystal projector comprising the dye-based polarizing film according to  claim 11 . 
     
     
         20 . A liquid crystal display equipped with the dye-based polarizing plate according to  claim 17 .