Chemically temperable glass sheet

Abstract

The invention relates to a glass sheet having a boron-, strontium- and lithium-free glass composition comprising the following in weight percentage, expressed with respect to the total weight of glass: 65≦SiO 2 ≦78%; 8≦Na 2 O≦15%; 1≦K 2 O<6%; 1≦Al 2 O 3 <6%; 2≦CaO<10%; 0≦MgO≦6%; as well as a K 2 O/(K 2 O+Na 2 O) ratio which is ranging from 0.1 and 0.7. The invention corresponds to an easy chemically-temperable soda-lime-silica type glass composition, which is more suited for use in electronic devices applications.

1 . A glass sheet having a boron-, strontium- and lithium-free glass composition, comprising the following in weight percentage, expressed with respect to the total weight of glass:
 65≦SiO 2 ≦78%;   5≦Na 2 O≦20%;   1≦K 2 O<8%;   1≦Al 2 O 3 <6%;   2≦CaO<10%;   0≦MgO≦8%; and   K 2 O/(K 2 O+Na 2 O) ratio which is from 0.1 to 0.7.   
     
     
         2 . The glass sheet according to  claim 1 , wherein the composition comprises total iron, expressed in the form of Fe 2 O 3 , in a content ranging from 0.002 to 1.7% by weight. 
     
     
         3 . The glass sheet according to  claim 2 , wherein the composition comprises total iron, expressed in the form of Fe 2 O 3 , in a content ranging from 0.002 to 0.6% by weight. 
     
     
         4 . The glass sheet according to  claim 3 , wherein the composition comprises total iron, expressed in the form of Fe 2 O 3 , in a content ranging from 0.002 to 0.2% by weight. 
     
     
         5 . The glass sheet according to  claim 1 , wherein the composition comprises total iron as follows:
 0.06<Fe 2 O 3 ≦1.7% by weight.   
     
     
         6 . The glass sheet according to  claim 5 , wherein the composition comprises total iron as follows:
 0.06<Fe 2 O 3 ≦0.6% by weight.   
     
     
         7 . The glass sheet according to  claim 6 , wherein the composition comprises total iron as follows:
 0.06<Fe 2 O 3 ≦0.2% by weight.   
     
     
         8 . The glass sheet according to  claim 7 , wherein the composition comprises a low alumina content such that:
 1≦Al 2 O 3 ≦4 wt %.   
     
     
         9 . The glass sheet according to  claim 8 , wherein the composition comprises:
 2≦Al 2 O 3 ≦3 wt %.   
     
     
         10 . The glass sheet according to  claim 1 , wherein the composition comprises:
 5≦CaO<10 wt %.   
     
     
         11 . The glass sheet according to  claim 1 , wherein the composition comprises:
 1≦K 2 O<6 wt %.   
     
     
         12 . The glass sheet according to  claim 1 , wherein the composition comprises:
 3≦K 2 O≦6 wt %.   
     
     
         13 . The glass sheet according to  claim 1 , wherein the composition comprises a K 2 O/(K 2 O+Na 2 O) ratio ranging from 0.1 to 0.5. 
     
     
         14 . The glass sheet according to  claim 1 , wherein the composition comprises a K 2 O/(K 2 O+Na 2 O) ratio ranging from 0.2 to 0.5. 
     
     
         15 . The glass sheet according to  claim 1 , wherein the composition comprises a K 2 O/(K 2 O+Na 2 O) ratio ranging from 0.2 to 0.4.