Azo Compound and Salt Thereof, And Dye-Based Polarizing Film And Polarizing Plate Containing The Same

Abstract

The present invention relates to an azo compound represented by the following formula (1) [wherein, A represents a naphthyl group having 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 a benzoylamino group having a substituent, a phenylamino group having a substituent, a phenylazo group having a substituent, or a naphthotriazole group having a substituent] and a salt thereof. By using the azo compound or a salt thereof of the present invention, a neutral color polarizing plate and a color polarizing plate for a liquid crystal projector being excellent in polarization performance and durability and having less color leakage in a visible light region can be provided.

1 . An azo compound represented by the following formula (1): 
       
         
           
           
               
               
           
         
       
       wherein, A represents a naphthyl group having 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 a phenylamino group having a substituent, a phenylazo group having a substituent, or a naphthotriazole group having a substituent and/or a salt thereof, wherein the phenylazo group having a substituent is represented by the following formula (5): 
       
         
           
           
               
               
           
         
       
       in the formula (5), 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 and/or a salt thereof according to  claim 1 , wherein X is a phenylamino group having a substituent, a phenylazo group having a substituent, or a naphthotriazole group having a substituent, and these substituents are groups selected from the group consisting of 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 hydroxy group, a carboxy group, a sulfo group, an amino group or a substituted amino group. 
     
     
         3 . The azo compound and/or a salt thereof according to  claim 1 , wherein X is a phenylamino group represented by the following formula (2): 
       
         
           
           
               
               
           
         
       
       in the formula (2), 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 and/or a salt thereof according to  claim 1 , wherein X is a naphthotriazole group represented by the following formula (4): 
       
         
           
           
               
               
           
         
       
       in the formula (4), m represents 1 or 2. 
     
     
         5 . The azo compound and/or a salt thereof according to  claim 1 , wherein A is a naphthyl group having at least one substituent and at least one of the substituents is a sulfo group. 
     
     
         6 . The azo compound and/or a salt thereof according to  claim 1 , wherein A is a naphthyl group represented by the following formula (6): 
       
         
           
           
               
               
           
         
       
       in the formula (6), R 13  represents a hydrogen atom, a hydroxy group, or an alkoxy group having a sulfo group and a carbon atom number of 1 to 5, and n represents 1 to 3. 
     
     
         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, or 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): 
       
         
           
           
               
               
           
         
       
       in the following formula (7), A, R 1  to R 6  and X have the same meanings as A, R 1  to R 6  and X in the formula (1). 
     
     
         9 . The azo compound and/or a salt thereof according to  claim 1 , wherein A is a naphthyl group substituted with 2 or 3 sulfo groups or a naphthyl group substituted with a 3-sulfopropoxy group and a sulfo group; R 1 , R 3  and R 5  are each independently a hydrogen atom, a methyl group, a methoxy group or a 3-sulfopropoxy group; R 2 , R 4  and R 6  are methyl groups; and X is any one group selected from the group consisting of an unsubstituted phenylamino group, a phenylamino group substituted with a methoxy group, and a naphthotriazole group substituted with 2 sulfo groups. 
     
     
         10 . A dye-based polarizing film containing the azo compound and/or a salt thereof according to  claim 1  in a raw film for a polarizing film. 
     
     
         11 . A dye-based polarizing film containing the azo compound and/or a salt thereof according to  claim 1  and one or more kinds of dichroic organic dyes other than it in a raw film for a polarizing film. 
     
     
         12 . A dye-based polarizing film containing two or more kinds of the azo compound and/or a salt thereof according to  claim 1  and one or more kinds of dichroic organic dyes other than it in a raw film for a polarizing film. 
     
     
         13 . A color dye-based polarizing film containing at least one kind of the azo compound and/or a salt thereof according to  claim 1  in a raw film for a polarizing film. 
     
     
         14 . The dye-based polarizing film according to  claim 10 , wherein the raw film for a polarizing film is a film comprising a polyvinyl alcohol resin, a vinyl alcohol copolymer resin or a modified form of a polyvinyl alcohol resin. 
     
     
         15 . The dye-based polarizing film according to  claim 14 , wherein the raw film for a polarizing film is a polyvinyl alcohol resin film. 
     
     
         16 . A dye-based polarizing plate with a transparent protective film attached to at least one surface of the dye-based polarizing film according to  claim 10 . 
     
     
         17 . A liquid crystal projector comprising the dye-based polarizing film according to  claim 1  or the dye-based polarizing plate with a transparent protective film attached to at least one surface of the dye-based polarizing film. 
     
     
         18 . A liquid crystal display comprising the dye-based polarizing plate according to  claim 16 . 
     
     
         19 . A dye-based polarizing film containing the azo compound and/or a salt thereof according to  claim 9  in a raw film for a polarizing film. 
     
     
         20 . A dye-based polarizing film containing the azo compound and/or a salt thereof according to  claim 9  and one or more kinds of dichroic organic dyes other than it in a raw film for a polarizing film. 
     
     
         21 . A dye-based polarizing film containing two or more kinds of the azo compound and/or a salt thereof according to  claim 1  and one or more kinds of dichroic organic dyes other than it in a raw film for a polarizing film. 
     
     
         22 . The dye-based polarizing film according to  claim 19 , wherein the raw film for a polarizing film is a film comprising a polyvinyl alcohol resin, a vinyl alcohol copolymer resin or a modified form of a polyvinyl alcohol resin. 
     
     
         23 . The dye-based polarizing film according to  claim 22 , wherein the raw film for a polarizing film is a polyvinyl alcohol resin film. 
     
     
         24 . A dye-based polarizing plate with a transparent protective film attached to at least one surface of the dye-based polarizing film according to  claim 19 . 
     
     
         25 . A liquid crystal display comprising the dye-based polarizing plate according to  claim 24 .