Optically detectable, floatable arsenic- and antimony-free, glazable lithium-aluminosilicate glass

Abstract

An optically detectable, floatable arsenic- and antimony-free, glazable lithium-aluminosilicate glass that can be prestressed and the glass ceramic converted therefrom are described. The glass or the glass ceramic has a composition (in % by weight based on oxide) of essentially SiO 2 55-69, Al 2 O 3 19-25, Li 2 O 3.2-5, Na 2 O 0-1.5, K 2 O 0-1.5, MgO 0-2.2, CaO 0-2.0, SrO 0-2.0, BaO 0-2.5, ZnO 0-<1.5, TiO 2 1-3, ZrO 2 1-2.5, SnO 2 0.1-<1, Σ TiO 2 +ZrO 2 +SnO 2 2.5-5, P 2 O 5 0-3, Nd 2 O 3 0.01-0.6, CoO 0-0.005, F 0-1, B 2 O 3 0-2.

1 . Optically detectable, floatable arsenic- and antimony-free, glazable lithium-aluminosilicate glass that can be prestressed and the glass ceramic that is converted therefrom with a composition of essentially (in % by weight based on oxide):  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 SiO 2   
                 55-69 
               
                   
                 Al 2 O 3   
                 19-25 
               
                   
                 Li 2 O 
                 3.2-5   
               
                   
                 Na 2 O 
                   0-1.5 
               
                   
                 K 2 O 
                   0-1.5 
               
                   
                 MgO 
                   0-2.2 
               
                   
                 CaO 
                   0-2.0 
               
                   
                 SrO 
                   0-2.0 
               
                   
                 BaO 
                   0-2.5 
               
                   
                 ZnO 
                   0-<1.5 
               
                   
                 TiO 2   
                 1-3 
               
                   
                 ZrO 2   
                   1-2.5 
               
                   
                 SnO 2   
                 0.1-<1  
               
                   
                 Σ TiO 2  + ZrO 2  + SnO 2   
                 2.5-5   
               
                   
                 P 2 O 5   
                 0-3 
               
                   
                 Nd 2 O 3   
                 0.0-0.6 
               
                   
                 CoO 
                    0-0.005 
               
                   
                 F 
                 0-1 
               
                   
                 B 2 O 3   
                 0-2 
               
                   
                   
               
                   
                   
               
           
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       2 . Glass and glass ceramic according to  claim 1 , characterized in that the sum of Na 2 O+K 2 O is 0.1-2% by weight.  
   
   
       3 . Glass and glass ceramic according to  claim 1  or  2 , wherein the sum of 3.2ZnO+TiO 2  is a maximum of 4.3% by weight.  
   
   
       4 . Glass or glass ceramic according to at least one of  claims 1  to  3  with a composition of essentially (in % by weight based on oxide):  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 SiO 2   
                 60-68 
               
                   
                 Al 2 O 3   
                 19-24 
               
                   
                 Li 2 O 
                 3.5-4.5 
               
                   
                 ΣNa 2 O 
                 0.2-1   
               
                   
                 K 2 O 
                   0-0.8 
               
                   
                 Na 2 O + K 2 O 
                 0.4-1.5 
               
                   
                 MgO 
                 0.1-2   
               
                   
                 CaO 
                 0-1 
               
                   
                 SrO 
                 0-1 
               
                   
                 BaO 
                   0-2.5 
               
                   
                 ZnO 
                 0-1 
               
                   
                 TiO 2   
                   1-2.6 
               
                   
                 ZrO 2   
                 1.2-2.2 
               
                   
                 SnO 2   
                 0.2-0.6 
               
                   
                 Σ TiO 2  + ZrO 2  + SnO 2   
                   3-4.5 
               
                   
                 P 2 O 5   
                 0-2 
               
                   
                 Nd 2 O 3   
                 0.025-0.46  
               
                   
                 CoO 
                     0-0.003. 
               
                   
                   
               
                   
                   
               
           
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       5 . Glass or glass ceramic according to one or more of claims  1 - 4 , wherein the sum of Li 2 O+Na 2 O is at least 3.7.  
   
   
       6 . Glass and glass ceramic according to one or more of claims  1 - 5  containing 
 less than 2.3 TiO 2      less than 0.4 Nd 2 O 3      less than 0.003 CoO    and, as a contaminant, less than 0.025 Fe 2 O 3 .    
   
   
       7 . Glass and glass ceramic according to one or more of claims  1 - 6 , wherein it or they, except for unavoidable contaminants, is or are free of BaO.  
   
   
       8 . Glass and glass ceramic according to one or more of  claims 1  to  7 , characterized by a content of less than 300 ppb of Pt and less than 30 ppb of Rh.  
   
   
       9 . Glass and glass ceramic according to one or more of claims  1 - 8 , characterized by a content of 100 to 3000 ppm of Nd 2 O 3 .