Plate-shaped pressed bodies

Abstract

There is disclosed a plate-shaped pressed body (wafer) produced from an inorganic sorbent and a binder, having a thickness of less than 700 μm, which is produced by the process of compressing a mixture of the inorganic sorbent, the binder, and optionally water and compression aids at a pressure of at least 70 MPa, wherein the weight ratio of dry sorbent to dry binder is between about 4 and 0.7 and the water content of the mixture, measured at 160° C., is between 8 and 20%; and calcining the resulting pressed body at temperatures of at least about 500° C., until the water content is substantially removed.

1 . A plate-shaped pressed body with a thickness of less than about 700 μm, comprising an inorganic sorbent and a binder wherein the pressed body is obtainable by the process comprising the steps of 
 compressing a mixture comprised of the inorganic sorbent and the binder at a pressure of at least about 70 MPa, wherein the weight ratio of the sorbent to the binder in the mixture is between about 4:1 and 0.7:1 when measured on a dry weight basis and wherein the water content of the mixture determined at 160° C. is between about 8 and 20 percent, and  
 calcining the resulting compressed mixture at a temperature of at least about 500° C. to form the pressed body, wherein water contained in the calcined pressed body is less than about 2 percent.  
 
     
     
         2 . The pressed body of  claim 1  wherein the mixture further comprises a compression aid.  
     
     
         3 . The pressed body of  claim 2  wherein the compression aid comprises a fatty acid salt of a divalent or trivalent metal.  
     
     
         4 . The pressed body of  claim 1  wherein the calcining is continued until the pressed body has a constant weight.  
     
     
         5 . The pressed body of  claim 1  wherein the calcining is continued until the residual moisture content of the pressed body is less than about 1 percent by weight.  
     
     
         6 . The pressed body of  claim 1  wherein the inorganic sorbent comprises a natural or synthetic zeolite.  
     
     
         7 . The pressed body of  claim 1  wherein the binder comprises a smectite clay.  
     
     
         8 . The pressed body of  claim 7  wherein the smectite clay comprises bentonite.  
     
     
         9 . The pressed body of  claim 1  wherein the pressed body has a thickness from about 200 to about 400 μm.  
     
     
         10 . The pressed body of  claim 1  wherein the ratio of the sorbent to the binder in the mixture on a dry weight basis is between 1.5 to 1 and 1 to 1.  
     
     
         11 . The pressed body of  claim 1  wherein the mixture of sorbent and binder are compressed at a pressure from about 100 to about 1300 MPa.  
     
     
         12 . The pressed body of  claim 1  wherein the mixture comprises particles, wherein not more than 15 percent of the particles are greater than about 250 μm in diameter.  
     
     
         13 . The pressed body of  claim 1  wherein the mixture comprises particles, wherein not more than 8 percent of the particles are greater than about 200 μm in diameter.  
     
     
         14 . The pressed body of  claim 1  wherein the mixture comprises particles, wherein not more than 8 percent of the particles are greater than about 150 μm in diameter.  
     
     
         15 . The pressed body of  claim 1  wherein the mixture comprises particles, wherein at least about 50 percent of the particles are greater than 45 μm in diameter.  
     
     
         16 . The pressed body of  claim 1  wherein the mixture comprises particles, wherein at least about 60 percent of the particles are greater than 45 μm in diameter.  
     
     
         17 . The pressed body of  claim 1  wherein the mixture comprises at least about 50 percent spherical particles.  
     
     
         18 . The pressed body of  claim 1  wherein the mixture comprises at least about 80 percent spherical particles.  
     
     
         19 . The pressed body of  claim 1  wherein the mixture comprises at least about 98 percent spherical particles.  
     
     
         20 . The pressed body of  claim 1  wherein the mixture is spray dried prior to compressing.  
     
     
         21 . The pressed body of  claim 1  wherein the compressed mixture is calcined under vacuum.  
     
     
         22 . The pressed body of  claim 1  wherein the pressed body is calcined under pressure in a perforated tube.  
     
     
         23 . A process for producing pressed bodies comprising 
 mixing an inorganic sorbent and a binder to form a mixture and pressing said mixture at a pressure of at least about 70 MPa, wherein the weight ratio of the sorbent to the binder is between about 4:1 and about 0.7:1 and the water content of the mixture measured at 150° is between about 8 and 20 percent, and calcining the pressed bodies at temperatures of about 500° C. until the water content is less than about 2 percent to form the pressed bodies.    
     
     
         24 . A process for removing moisture from an electronic device by placing the pressed body of  claim 1  within the electronic device.