Method for producing a hygroscopic agent

Abstract

An organic electroluminescence display includes a transparent glass substrate, an ITO anode layer, a positive hole transition layer, an RGB luminescence layer, an electron transition layer and a metallic cathode layer. Highly pressurized N 2 gas is sealed in the interior of the display. To absorb and retain the moisture in the sealed gas, a hygroscopic member is disposed between a sealing member and the cathode layer. The hygroscopic member includes a nonwoven fabric including a fiber layer made of fibers bonding to each other and a hygroscopic agent adhering to one surface of the fiber layer and an air-permeable sheet covering the nonwoven fabric as a whole.

1 - 17 . (canceled)  
     
     
         18 . A method for producing a hygroscopic agent, comprising: 
 a first step of forming porous particles of silicon dioxide by drying wet gel; and    a second step of mixing at least one substance from among calcium oxide, calcium, calcium carbonate, barium oxide, fluoride resin, and fluorine resin, with said silicon dioxide, and letting said silicon dioxide adhere to an outer periphery of the substance.    
     
     
         19 . A method for producing a hygroscopic agent according to  claim 18 , wherein said first step is a step of drying the wet gel by gradually raising an ambient temperature to a range from approximately 135° C. to 150° C., thereby forming the porous particles of said silicon dioxide.  
     
     
         20 . A method for producing a hygroscopic agent according to  claim 19 , wherein said second step is a step of letting said silicon dioxide adhere to the outer periphery of said substance by mixing 50 to 70 parts of said silicon dioxide with 50 to 30 parts of the substance having a particle diameter of 150 μm or greater.  
     
     
         21 . A hygroscopic agent characterized in that silicon dioxide adheres to an outer periphery of at least one substance from among calcium oxide, calcium, calcium carbonate, barium oxide, fluoride resin, and fluorine resin.  
     
     
         22 . A hygroscopic agent according to  claim 21 , wherein said substance has a particle diameter of 140 μm to 150 μm.  
     
     
         23 . A hygroscopic agent according to  claim 21 , wherein said silicon dioxide has a particle diameter of 5 μm to 10 μm.