Photo-responsive high-molecular compound, photo-responsive high-molecular composition, dicarboxylic acid monomer, polyester, optical recording medium and optical record reproducing device

Abstract

In the present invention, a photosensitive layer of an optical recording medium includes a photo-responsive high-molecular compound comprising a photo-responsive group (e.g., an azobenzene derivative) which is geometrically isomerized by light radiation, and a liquid crystal linear mesogen group (e.g., a biphenyl derivative), wherein the photo-responsive group and the linear mesogen group are respectively bonded as side chains. The invention provides an optical recording medium enabling large scale recording by making the photosensitive layer thick without impairing recording characteristics. The photo-responsive high-molecular compound preferably comprises an aromatic ring on a main chain. Further, the photo-responsive high-molecular compound preferably comprises a structural unit which is capable of forming a liquid-crystalline or crystalline polymer and a structural unit which is capable of forming an amorphous polymer.

What is claimed is:  
     
         1 . A photo-responsive high-molecular compound comprising a photo-responsive group which is geometrically isomerized by light radiation, and a liquid crystal linear mesogen group, wherein the photo-responsive group and the linear mesogen group are respectively bonded as side chains.  
     
     
         2 . A photo-responsive high-molecular compound comprising an aromatic ring on a main chain, a photo-responsive group which is geometrically isomerized by light radiation, and a liquid crystal linear mesogen group, wherein the photo-responsive group and the liquid crystal linear mesogen group are respectively bonded with the aromatic ring as side chains.  
     
     
         3 . A photo-responsive high-molecular compound according to  claim 1 , wherein the main chain comprises a structural unit which is capable of forming a liquid-crystalline or crystalline polymer and a structural unit which is capable of forming an amorphous polymer.  
     
     
         4 . A photo-responsive high-molecular compound according to  claim 1 , wherein the photo-responsive group contains an azobenzene skeleton.  
     
     
         5 . A photo-responsive high-molecular compound according to  claim 1 , wherein the liquid crystal linear mesogen group contains a biphenyl skeleton.  
     
     
         6 . A photo-responsive high-molecular composition comprising: 
 a photo-responsive high-molecular compound in which a photo-responsive group to be geometrically isomerized by light radiation is bonded as a side chain; and    a photo-unresponsive high-molecular compound in which a liquid crystal linear mesogen group is bond as a side chain.    
     
     
         7 . A photo-responsive high-molecular composition comprising: 
 a photo-responsive high-molecular compound containing an aromatic ring on a main chain and a photo-responsive group which is geometrically isomerized by light radiation and bonded with the aromatic ring as side chains; and    a photo-unresponsive high-molecular compound containing an aromatic ring on a main chain and a liquid crystal linear mesogen group bonded with the aromatic ring as side chains.    
     
     
         8 . A photo-responsive high-molecular composition according to  claim 6 , wherein the main chain comprises a structural unit which is capable of forming a liquid-crystalline or crystalline polymer and a structural unit which is capable of forming an amorphous polymer.  
     
     
         9 . A photo-responsive high-molecular composition according to  claim 6 , wherein the photo-responsive group contains an azobenzene skeleton.  
     
     
         10 . A photo-responsive high-molecular composition according to  claim 6 , wherein the liquid crystal linear mesogen group contains a biphenyl skeleton.  
     
     
         11 . A dicarboxylic acid monomer represented by the following general formula (1):  
       General formula (1)  
       
         
           
           
               
               
           
         
         wherein X represents a lower alkyloxy group, a substituted or unsubstituted benzyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, an acid residue of a substituted or unsubstituted benzoic acid, or a halogen atom; Y represents a hydrogen atom or a lower alkyl group; Z represents a hydrogen atom, a methyl group, a methoxy group, a cyano group, or a nitro group; m denotes an integer from 1 to 3; and n denotes an integer from 2 to 18.  
       
     
     
         12 . A polyester represented by the following general formula (4):  
       
         
           
           
               
               
           
         
         wherein Y represents a hydrogen atom or a lower alkyl group; Z represents a hydrogen atom, a methyl group, a methoxy group, a cyano group, or a nitro group; R represents a hydrocarbon chain which may contain at least one of a substituted or unsubstituted aromatic group and a substituted or unsubstituted aliphatic group; m denotes an integer from 1 to 3; n denotes an integer from 2 to 18; and p denotes an integer from 5 to 2000.  
       
     
     
         13 . A polyester according to  claim 12 , wherein R in the general formula (4) comprises a structural unit which is capable of forming a liquid-crystalline or crystalline polymer and a structural unit which is capable of forming an amorphous polymer.  
     
     
         14 . A polyester according to  claim 12 , wherein R in the general formula (4) is a functional group represented by the following general formula (5):  
       
         
           
           
               
               
           
         
         wherein U represents a hydrogen atom, a halogen atom, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group, or a substituted or unsubstituted lower alkinyl group; T represents a direct bond, a sulfone bond, a sulfoxide bond, an ether bond, a thioether bond, a substituted imino bond, or a ketone bond; q denotes an integer from 1 to 4; and 1 denotes an integer from 2 to 18.  
       
     
     
         15 . A polyester comprising a repeat unit represented by the following general formula (6):  
       
         
           
           
               
               
           
         
         wherein Y and Y′ each independently represent a hydrogen atom or a lower alkyl group; Z and Z′ each independently represent a hydrogen atom, a methyl group, a methoxy group, a cyano group or a nitro group; R represents a hydrocarbon chain containing a substituted or unsubstituted aromatic group, a substituted or unsubstituted aliphatic group; m and m′ each independently denote an integer from 1 to 3; n and n′ respectively denote an integer from 2 to 18; p denotes an integer from 5 to 2000; and x and y respectively represent abundance ratios of the repeat unit and fulfill the following relationships: 0<x≦1, 0≦y<1 and x+y=1.  
       
     
     
         16 . A polyester according to  claim 15 , wherein R in the general formula (6) is a functional group represented by the following general formula (5):  
       
         
           
           
               
               
           
         
         wherein U represents a hydrogen atom, a halogen atom, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group, or a substituted or unsubstituted lower alkinyl group; T represents a direct bond, a sulfone bond, a sulfoxide bond, an ether bond, a thioether bond, a substituted imino bond, or a ketone bond; q denotes an integer from 1 to 4; and 1 denotes an integer from 2 to 18.  
       
     
     
         17 . A polyester comprising a repeat unit represented by the following general formula (10):  
       
         
           
           
               
               
           
         
         wherein R 1  represents a structural unit capable of forming a liquid-crystalline or crystalline polymer; R 2  represents a structural unit capable of forming an amorphous polymer; Y and Y′ respectively represent a hydrogen atom or a lower alkyl group; Z and Z′ each independently represent a hydrogen atom, a methyl group, a methoxy group, a cyano group or a nitro group; R represents a hydrocarbon chain including a substituted or unsubstituted aromatic group, a substituted or unsubstituted aliphatic group or both of a substituted or unsubstituted aromatic group and a substituted or unsubstituted aliphatic group; m and m′ each independently represent an integer from 1 to 3; n and n′ each independently represent an integer from 2 to 18; p represents an integer from 5 to 2000; and x, y, r and s each independently represent the abundance ratio of the repeat unit wherein x, y, r and s satisfy the following relations: 0<x≦1, 0≦y<1, x+y=1, 0≦r≦1, 0≦s≦1 and r+s=1.  
       
     
     
         18 . An optical recording medium provided with a photosensitive layer containing a photo-responsive high-molecular compound comprising a photo-responsive group which is geometrically isomerized by light radiation and a liquid crystal linear mesogen group, the photo-responsive group and the liquid crystal linear mesogen group being respectively bonded therewith as side chains, wherein information is recorded in the photosensitive layer by utilizing at least one of a change in absorption, a change in refractive index, and a change in shape, due to light radiation.  
     
     
         19 . An optical recording medium provided with a photosensitive layer containing a photo-responsive high-molecular composition comprising: 
 a photo-responsive high-molecular compound in which a photo-responsive group to be geometrically isomerized by light radiation is bonded as a side chain; and    a photo-unresponsive high-molecular compound in which a liquid crystal linear mesogen group is bond as a side chain,    wherein information is recorded in the photosensitive layer by utilizing at least one of a change in absorption, a change in refractive index, and a change in shape, due to light radiation.    
     
     
         20 . An optical recording medium provided with a photosensitive layer containing a polyester, the recording medium recording information in the photosensitive layer by utilizing at least one of a change in absorption, a change in refractive index, and a change in shape, due to light radiation, wherein the polyester is represented by the following general formula (4):  
       
         
           
           
               
               
           
         
         wherein Y represents a hydrogen atom or a lower alkyl group; Z represents a hydrogen atom, a methyl group, a methoxy group, a cyano group or a nitro group; R represents a hydrocarbon chain which may contain at least one of a substituted or unsubstituted aromatic group and a substituted or unsubstituted aliphatic group; m denotes an integer from 1 to 3; n denotes an integer from 2 to 18; and p denotes an integer from 5 to 2000.  
       
     
     
         21 . An optical recording medium according to claim  18 , wherein the photosensitive layer has a thickness of 50 μm or more.  
     
     
         22 . An optical recording medium according to  claim 18 , wherein recording of a hologram is possible.  
     
     
         23 . An optical recording medium according to  claim 18 , wherein recording of a hologram is independently possible in each of a case where a polarization direction of light that is incident on an object and a polarization direction of reference light are parallel to each other, and a case where polarization direction of light that is incident on an object and a polarization direction of reference light are perpendicular to each other.  
     
     
         24 . An optical recording medium according to  claim 18 , wherein recording of a hologram by the amplitude, phase and direction of polarization of object light is possible.  
     
     
         25 . An optical recording reproducing device for recording and/or reproducing information by using an optical recording medium provided with a photosensitive layer containing a photo-responsive high-molecular compound comprising a photo-responsive group which is geometrically isomerized by light radiation, and a liquid crystal linear mesogen group, the photo-responsive group and the linear mesogen group being respectively bonded as side chains, wherein information is recorded in the photosensitive layer by utilizing at least one of a change in absorption, a change in refractive index, and a change in shape, due to light radiation.