Optical recording medium

Abstract

An optical recording material for use in an optical recording layer of an optical recording medium comprising the optical recording layer provided on a substrate, the optical recording material comprising a cyanine compound represented by general formula (I): wherein rings A and B each represent a substituted or unsubstituted benzene or naphthalene ring; X represents O, S, Se, CR 3 R 4 or NY; one of R 1 and R 2 represents a specific group of formula (II) or (III), with the other representing a C1 to C30 organic group; R 3 and R 4 each represent a C1 to C30 organic group; Y, Y 1 , and Y 2 each represent a hydrogen atom or a C1 to C30 organic group; Z represents a hydrogen atom, a halogen atom or a cyano group; An m−1 represents an m-valent anion; m represents an integer of 1 or 2; and p represents a coefficient maintaining charge neutrality.

1 . An optical recording medium comprising:
 a substrate, and   a thin film of an optical recording material on the substrate,   wherein the optical recording material comprises a cyanine compound represented by general formula (I):   
     
       
         
         
             
             
         
       
     
     wherein ring A and ring B each represent a benzene ring optionally having a substituent or a naphthalene ring optionally having a substituent; X represents O, S, Se, CR 3 R 4  or NY; one of R 1  and R 2  represents a group represented by general formula (II) or (III) below, with the other representing an organic group having 1 to 30 carbon atoms; R 3  and R 4  each represent an organic group having 1 to 30 carbon atoms; Y, Y 1 , and Y 2  each represent a hydrogen atom or an organic group having 1 to 30 carbon atoms; Z represents a hydrogen atom, a halogen atom or a cyano group; An m−1  represents an m-valent anion; m represents an integer of 1 or 2; and p represents a coefficient maintaining charge neutrality, wherein the bond between E and G is a double bond or a triple bond; E represents a carbon atom; G represents a carbon atom, an oxygen atom or a nitrogen atom; x, y, and z each independently represent 0 or 1; R 5  represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms and optionally substituted with a halogen atom or an alkoxy group having 1 to 4 carbon atoms and optionally substituted with a halogen atom; R 6 , R 7 , and R 8  each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 
     
       
         
         
             
             
         
       
     
     carbon atoms and optionally substituted with a halogen atom; R 6  and R 8  may be connected to each other to form a cyclic structure. 
     
       
         
         
             
             
         
       
     
     wherein the bond between E′ and G′ is a double bond; E′ represents a carbon atom; G′ represents a carbon atom, an oxygen atom or a nitrogen atom; the ring containing E′ and G′ is a 5-membered ring optionally containing a hetero atom, a heterocyclic 6-membered ring, a naphthalene ring, a quinoline ring, an isoquinoline ring, an anthracene ring or an anthraquinone ring; the ring containing E′ and G′ may be substituted with at least one substituent selected from the group consisting of a halogen atom, a nitro group, a cyano group, an alkyl group, and an alkoxy group.