Optical recording medium, azo-type iron chelate coloring matter, and azo-type metal chelate coloring matter additive

Abstract

An optical recording medium, which makes information be recorded and read with light having wavelength of 700 nm or shorter, with excellent light resistance, high-speed recording and high-density recording is provided. The optical recording medium comprises a substrate, a recording layer formed on the substrate and containing a host dye, which can make information be recorded or read by being irradiated with light having wavelength of 700 nm or shorter, and a reflective layer. The recording layer contains at least an azo metal-chelate dye additive, of which central metal ion is any one of Cu 2+ , Fe 2+ and Co 2+ .

1 . An optical recording medium comprising a substrate, a recording layer formed on said substrate and containing a host dye, which can make information be recorded or read by being irradiated with light having wavelength of 700 nm or shorter, and a reflective layer;
 wherein said recording layer contains at least one azo metal-chelate dye additive, of which the central metal ion is any one of Cu 2+ , Fe 2+  and Co 2+ .   
   
   
       2 . The optical recording medium as defined in  claim 1 , wherein the central metal ion of said azo metal-chelate dye additive is either Fe 2+  or Co + . 
   
   
       3 . The optical recording medium as defined in  claim 1 , wherein said azo metal-chelate dye additive is contained in said host dye of said recording layer with the concentration of 0.1 weight % or more and 50 weight % or less. 
   
   
       4 . The optical recording medium as defined in  claim 1 , wherein said azo metal-chelate dye additive has, in a state of film or solution, one or more absorption maximums at wavelength ranges of 400 nm to 630 nm and 680 nm to 800 nm respectively. 
   
   
       5 . The optical recording medium as defined in  claim 1 , wherein said recording layer has one or more absorption maximums at wavelength ranges of 400 nm to 630 nm and 680 nm to 800 nm respectively. 
   
   
       6 . The optical recording medium as defined in  claim 1 , wherein said host dye is an azo metal-chelate dye comprising a ligand, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (I) below, and Zn 2+ : 
     
       
         
         
             
             
         
       
     
     where for general formula (I),
 ring A is an aromatic heterocycle, which may have a substituent; 
 X is an organic group having active hydrogen; and 
 ring B is an aromatic ring or aromatic heterocycle, which may have a substituent in addition to X. 
 
   
   
       7 . The optical recording medium as defined in  claim 1 , wherein said host dye is a cyanine dye represented by general formula (II) below: 
     
       
         
         
             
             
         
       
     
     where for general formula (II),
 ring C and ring D each represents, independently of each other, an indolenin ring, 
 benzoindolenin ring or dibenzoindolenin ring; 
 L represents a monomethine group or trimethine group; and 
 R 1  and R 2  each represents, independently of each other, an alkyl group, which may have a substituent. 
 
   
   
       8 . An azo iron chelate dye comprising two ligands, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (III) below respectively, and Fe 2+ : 
     
       
         
         
             
             
         
       
     
     where for general formula (III),
 ring E is an aromatic heterocycle, which may have a substituent; 
 X is an organic group having active hydrogen; and 
 R 3  and R 4  each represents, independently of each other, an alkyl group, which may have a substituent or R 3  and R 4  may be connected to each other to form a ring, and either one or both of R 3  and R 4  may be connected to a benzene ring to form a 4 to 7 membered ring, which may be condensed to form a benzene ring wherein 
 
     all of rings E, X, R 3  and R 4 , belonging to the two ligands, may be the same as or different from each other. 
   
   
       9 . An azo metal-chelate dye additive to be used for a recording layer of an optical recording medium,
 wherein said azo metal-chelate dye additive comprises said azo iron chelate dye as defined in  claim 8 .   
   
   
       10 . An azo metal-chelate dye additive to be used for a recording layer of an optical recording medium,
 wherein said azo metal-chelate dye additive comprises two ligands, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (IV) below respectively, and Co 2+ , and   said azo metal-chelate dye additive has, in a state of film or solution, one or more absorption maximums at wavelength ranges of 400 nm to 630 nm and 680 nm to 800 nm respectively:   
     
       
         
         
             
             
         
       
     
     where for general formula (IV),
 ring E is an aromatic heterocycle, which may have a substituent; 
 X is an organic group having active hydrogen; and 
 R 3  and R 4  each represents, independently of each other, an alkyl group, which may have a substituent or R 3  and R 4  may be connected to each other to form a ring, and either one or both of R 3  and R 4  may be connected to a benzene ring to form a 4 to 7 membered ring, which may be condensed to form a benzene ring wherein 
 
     all of rings E, X, R 3  and R 4 , belonging to the two ligands, may be the same as or different from each other. 
   
   
       11 . The optical recording medium as defined in  claim 6 , wherein said azo metal-chelate dye additive comprises an azo iron chelate dye comprising two ligands, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (III) below respectively, and Fe 2+ : 
     
       
         
         
             
             
         
       
     
     where for general formula (III),
 ring E is an aromatic heterocycle, which may have a substituent; 
 X is an organic group having active hydrogen; and 
 R 3  and R 4  each represents, independently of each other, an alkyl group, which may have a substituent or R 3  and R 4  may be connected to each other to form a ring, and either one or both of R 3  and R 4  may be connected to a benzene ring to form a 4 to 7 membered ring, which may be condensed to form a benzene ring wherein 
 
     all of rings E, X, R 3  and R 4 , belonging to the two ligands, may be the same as or different from each other. 
   
   
       12 . The optical recording medium as defined in  claim 7 , wherein said azo metal-chelate dye additive comprises an azo iron chelate dye comprising two ligands, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (III) below respectively, and Fe 2+ : 
     
       
         
         
             
             
         
       
     
     where for general formula (III),
 ring E is an aromatic heterocycle, which may have a substituent; 
 X is an organic group having active hydrogen; and 
 R 3  and R 4  each represents, independently of each other, an alkyl group, which may have a substituent or R 3  and R 4  may be connected to each other to form a ring, and either one or both of R 3  and R 4  may be connected to a benzene ring to form a 4 to 7 membered ring, which may be condensed to form a benzene ring wherein 
 
     all of rings E, X, R 3  and R 4 , belonging to the two ligands, may be the same as or different from each other. 
   
   
       13 . The optical recording medium as defined in  claim 6 , wherein said azo metal-chelate dye additive comprises two ligands, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (IV) below respectively, and Co 2+ , and
 said azo metal-chelate dye additive has, in a state of film or solution, one or more absorption maximums at wavelength ranges of 400 nm to 630 nm and 680 nm to 800 nm respectively:   
     
       
         
         
             
             
         
       
     
     where for general formula (IV),
 ring E is an aromatic heterocycle, which may have a substituent; 
 X is an organic group having active hydrogen; and 
 R 3  and R 4  each represents, independently of each other, an alkyl group, which may have a substituent or R 3  and R 4  may be connected to each other to form a ring, and either one or both of R 3  and R 4  may be connected to a benzene ring to form a 4 to 7 membered ring, which may be condensed to form a benzene ring wherein 
 
     all of rings E, X, R 3  and R 4 , belonging to the two ligands, may be the same as or different from each other. 
   
   
       14 . The optical recording medium as defined in  claim 7 , wherein said azo metal-chelate dye additive comprises two ligands, where active hydrogen contained in X is eliminated from an azo compound represented by general formula (IV) below respectively, and Co 2+ , and
 said azo metal-chelate dye additive has, in a state of film or solution, one or more absorption maximums at wavelength ranges of 400 nm to 630 nm and 680 nm to 800 nm respectively:   
     
       
         
         
             
             
         
       
       where for general formula (IV), 
       ring E is an aromatic heterocycle, which may have a substituent; 
       X is an organic group having active hydrogen; and 
       R 3  and R 4  each represents, independently of each other, an alkyl group, which may have a substituent or R 3  and R 4  may be connected to each other to form a ring, and either one or both of R 3  and R 4  may be connected to a benzene ring to form a 4 to 7 membered ring, which may be condensed to form a benzene ring wherein 
     
     all of rings E, X, R 3  and R 4 , belonging to the two ligands, may be the same as or different from each other.