Glass composition and process for producing glass composition

Abstract

A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition contains, in terms of mass %: 40-70% SiO 2 ; 5-20% B 2 O 3 ; 10-25% Al 2 O 3 ; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0-0.5% Li 2 O; 0-1.0% Na 2 O; 0-1.5% K 2 O; and 0-1.5%, excluding 0%, Cl, Li 2 O+Na 2 O+K 2 O exceeding 0.06%. The glass composition can be produced suitably using, for example, a chloride as part of the raw glass materials.

1 . A glass substrate consisting of a glass composition that comprises, in mass %,
 40 to 70% SiO 2 ,   5 to 20% B 2 O 3 ,   10 to 25% Al 2 O 3 ,   0 to 10% MgO,   0 to 20% CaO,   0 to 20% SrO, and   0 to 10% BaO,   and further comprises greater than 0.06% R 2 O,   where R is at least one selected from Li, Na, and K, and Li 2 O falls in a range of 0 to 0.5%, Na 2 O falls in a range of 0 to 1.0%, and K 2 O falls in a range of 0 to 1.5%, all in mass %.   
     
     
         2 . The glass substrate according to  claim 1 , wherein the glass composition further comprises greater than 0% and no greater than 1.5% Cl. 
     
     
         3 . The glass substrate according to  claim 1 , wherein the R 2 O content is in a range of greater than 0.07%, in mass %. 
     
     
         4 . The glass substrate according to  claim 1 , wherein the R 2 O content is in a range of greater than 0.06% to no greater than 1.5%, in mass %. 
     
     
         5 . The glass substrate according to  claim 1 , wherein the Na 2 O content is in a range of 0 to 0.5%, in mass %. 
     
     
         6 . The glass substrate according to  claim 1 , wherein the K 2 O content is in a range of 0.05 to 1.5%, in mass %. 
     
     
         7 . The glass substrate according to  claim 1 , wherein the Li 2 O content is in a range of 0.015 to 0.5%, in mass %. 
     
     
         8 . The glass substrate according to  claim 1 , which comprises 58 to 70% SiO 2 , 8 to 13% B 2 O 3 , 13 to 20% Al 2 O 3 , 1 to 5% MgO, 1 to 10% CaO, 0 to 4% SrO, and 0 to 1% BaO, all in mass %. 
     
     
         9 . The glass substrate according to  claim 1 , which comprises 57 to 65% SiO 2 , 5 to 12% B 2 O 3 , 10 to 20% Al 2 O 3 , 5 to 10% MgO, 0 to 10% CaO, and 0 to 10% SrO, all in mass %. 
     
     
         10 . The glass substrate according to  claim 1 , which comprises 60 to 65% SiO 2 , 5 to 12% B 2 O 3 , 10 to 20% Al 2 O 3 , 0 to 5% MgO, 1 to 6% CaO, 0 to 10% SrO, and 0 to 1% BaO, all in mass %. 
     
     
         11 . The glass substrate according to  claim 10 , which comprises 9 to 12% B 2 O 3 , 10 to 15% Al 2 O 3 , and 1 to 5% MgO, all in mass %. 
     
     
         12 . The glass substrate according to  claim 1 , which comprises 56 to 65% SiO 2 , 5 to 12% B 2 O 3 , 10 to 18% Al 2 O 3 , 0 to 5% MgO, 1 to 10% CaO, 1 to 10% SrO, and 0 to 1% BaO, all in mass %. 
     
     
         13 . The glass substrate according to  claim 12 , which comprises 2 to 5% MgO, and 3 to 10% SrO, both in mass %. 
     
     
         14 . The glass substrate according to  claim 1 , which comprises 56 to 60% SiO 2 , 5 to 12% B 2 O 3 , 10 to 18% Al 2 O 3 , 0 to 5% MgO, 1 to 6% CaO, 1 to 6% SrO, and 3 to 10% BaO, all in mass %. 
     
     
         15 . The glass substrate according to  claim 1 , which comprises 58 to 64% SiO 2 , 8 to 12% B 2 O 3 , 5 to 18% Al 2 O 3 , 1 to 10% MgO, 2 to 10% CaO, 1.5 to 4.5% SrO, and 1 to 5% BaO, all in mass %. 
     
     
         16 . The glass substrate according to  claim 15 , which comprises 15 to 18% Al 2 O 3 , 1 to 5% MgO, 3 to 8% CaO, 2 to 4% SrO, and 1 to 4% BaO, all in mass %. 
     
     
         17 . The glass substrate according to  claim 16 , which comprises 1 to 2% MgO, in mass %. 
     
     
         18 - 26 . (canceled)