Liquid crystal display element and manufacturing method thereof

Abstract

The invention discloses a liquid crystal display element including: a pair of display substrates each having a support and an electrode provided on one surface of the support; and a display layer provided between the electrodes of the pair of display substrates, wherein the display layer contains gelatin and liquid crystal drops or microcapsules; and the liquid crystal drops or microcapsules are densely arrayed in a monolayer, and a method of manufacturing the liquid crystal display element, including: applying to a surface of one of the display substrates which surface has the electrode, a coating solution in which liquid crystal drops or microcapsules are dispersed in a solution containing gelatin and a solvent, thereby forming a coating layer; and evaporating the solvent in the coating layer at a temperature not less than the freezing point of the gelatin to provide a display layer between the electrodes of the display substrates.

1 . A liquid crystal display element comprising: 
 a pair of display substrates each having a support and an electrode provided on one surface of the support; and    a display layer provided between the electrodes of the pair of display substrates, wherein    the display layer contains gelatin and one of liquid crystal drops and liquid crystal microcapsules; and    the one of the liquid crystal drops and the liquid crystal microcapsules is densely arrayed in a monolayer.    
   
   
       2 . A liquid crystal display element according to  claim 1 , wherein the one of the liquid crystal drops and liquid crystal microcapsules is in a monodispersed state with uniform particle diameters.  
   
   
       3 . A liquid crystal display element according to  claim 2 , wherein the one of the liquid crystal drops and the liquid crystal microcapsules is prepared by a film-emulsifying process.  
   
   
       4 . A liquid crystal display element according to  claim 1 , wherein the gelatin is prepared by acid-treating cattle bone.  
   
   
       5 . A liquid crystal display element according to  claim 1 , wherein liquid crystal used for the one of the liquid crystal drops and the liquid crystal microcapsules is selected from the group consisting of cholesteric liquid crystal, nematic liquid crystal, guest liquid crystal and host liquid crystal.  
   
   
       6 . A liquid crystal display element according to  claim 1 , further comprising a light shielding layer on one electrode of the pair of display substrates.  
   
   
       7 . A liquid crystal display element according to  claim 6 , further comprising a bonding layer between the light shielding layer and the display layer.  
   
   
       8 . A liquid crystal display element according to  claim 1 , further comprising a bonding layer between the display layer and at least one of the electrodes.  
   
   
       9 . A liquid crystal display element according to  claim 6 , further comprising a bonding layer between the light shielding layer and one of the electrodes.  
   
   
       10 . A liquid crystal display element according to  claim 6 , further comprising a photoconductive layer between the light shielding layer and one of the electrodes.  
   
   
       11 . A liquid crystal display element according to  claim 1 , wherein the one of the liquid crystal drops and the liquid crystal microcapsules has a uniform size.  
   
   
       12 . A liquid crystal display element according to  claim 1 , wherein liquid crystal used for the one of the liquid crystal drops and the liquid crystal microcapsules is cholesteric liquid crystal.  
   
   
       13 . A method of manufacturing a liquid crystal display element according to  claim 1 , comprising: 
 applying to a surface of one of display substrates each having a support and an electrode provided on one surface of the support, which surface has the electrode, a coating solution for a display layer in which one of liquid crystal drops and liquid crystal microcapsules is dispersed in a solution containing gelatin and a solvent, the gelatin, the solvent, and the one of the liquid crystal drops and the liquid crystal microcapsules being in an adjusted mix proportion, thereby forming a coating layer; and    evaporating the solvent in the coating layer at a temperature equal to or higher than the freezing point of the gelatin to provide a display layer between the electrodes of the display substrates.    
   
   
       14 . A method of manufacturing a liquid crystal display element according to  claim 13 , wherein a coating portion is retained in an atmosphere of which the vapor pressure is the same as or close to the saturation vapor pressure of the solvent in a part or the total of time that the solvent is evaporated.  
   
   
       15 . A method of manufacturing a liquid crystal display element according to  claim 13 , wherein vibration is applied to the coating layer in a part or the total of time that the solvent is evaporated.  
   
   
       16 . A method of manufacturing a liquid crystal display element according to  claim 13 , wherein the one of the liquid crystal drops and the liquid crystal microcapsules is prepared by a film-emulsifying process.  
   
   
       17 . A method of manufacturing a liquid crystal display element according to  claim 13 , wherein a ratio A L  of an area covered by the one of the liquid crystal drops and the liquid crystal microcapsules to a coated area, calculated by the following formula (1), is adjusted to a range of the following formula (2), when a ratio of volume of nonvolatile components to volume of the coating solution for the display layer is denoted as Sr, a ratio of volume of the one of the liquid crystal drops and the liquid crystal microcapsules to volume of the nonvolatile components is denoted as Lr, an average particle diameter of the one of the liquid crystal drops and the liquid crystal microcapsule is denoted as D L  μm, and a wet coating thickness on the one of the display substrates is denoted as t W  μm.  
         A   L =(3/2)·( t   W   ·Sr·Lr/D   L )  Formula (1)  0.8<A L <1.0  Formula (2)  
   
   
       18 . A method of manufacturing a liquid crystal display element according to  claim 17 , wherein the ratio Lr of volume of the one of the liquid crystal drops and the liquid crystal microcapsules to volume of the nonvolatile components is adjusted to 0.9 or less.  
   
   
       19 . A method of manufacturing a liquid crystal display element according to  claim 13 , wherein the temperature of the coating solution for the display layer is adjusted to a range of 40 to 60° C.  
   
   
       20 . A method of manufacturing a liquid crystal display element according to  claim 13 , wherein the coating layer is dried at a temperature in a range of 40 to 60° C.