Glasses for display panels and photovoltaic devices

Abstract

An aluminosilicate glass having a composition consisting essentially of, as calculated in weight percent on an oxide basis, of 58-70% SiO 2 , 12-22% Al 2 O 3 , 3-15% B 2 O 3 , 2-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, 10-25% MCSB (i.e., MgO+CaO+SrO+BaO), and SrO and BaO in combination being less than 3%.

1. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion (CTE) over the temperature range 0-300° C. between 30-40×10 −7 /° C. and a strain point over 600° C.  650 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of 58-70% SiO 2 , 12-22% Al 2 O 3 , 3 5-15% B 2 O 3 , 2 5-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, and SrO and BaO in combination being less than 3%, said glass containing in addition to CaO, at least one of MgO, SrO, and BaO. 
     
     
       2. A substrate glass in accordance with  claim 1  which wherein the glass is manufactured by the float process, said glass having a liquidus viscosity greater than about  50 MPa·s Pa·s  (500 poises). 
     
     
       3. A substrate according to  claim 2 , wherein said glass has a CTE of 32-38×10 −7 /° C. and a strain point over 650° C. 
     
     
       4. A substrate according to  claim 3 , wherein said glass has a strain point over 675° C. 
     
     
       5. A substrate according to  claim 3 , wherein the combined SrO and BaO content of said glass is less than about 1 weight percent. 
     
     
       6. A substrate according to  claim 3 , wherein said glass is essentially free of SrO and BaO. 
     
     
       7. A flat panel display comprising a substrate in accordance with  claim 1 . 
     
     
       8. A substrate according to  claim 1 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-67%, SiO 2 , 15-20% Al 2 O 3 , 5-13% B 2 O 3 , 5-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, and SrO and BaO in combination is less than 3 wt %. 
     
     
       9. A substrate according to  claim 3 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-67% SiO 2 , 15-20% Al 2 O 3 , 5-13% B 2 O 3 , 5-12% CaO, 0-3% SrO, 0-3% BaO, 1-8% MgO, and SrO and BaO in combination is less than 3 wt %. 
     
     
       10. A substrate according to  claim 9 , wherein said glass has a strain point over 675° C. 
     
     
       11. A substrate according to  claim 9 , wherein the combined SrO and BaO content of said glass is less than about 1 weight percent. 
     
     
       12. A substrate according to  claim 9 , wherein the glass has a weight loss less than 5.0 mg/cm 2  when immersed in 5% HCl at 95° C. for one hour. 
     
     
       13. A substrate according to  claim 1 , wherein for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C.,  said glass consists essentially of an aluminosilicate having a composition, as calculated in weight percent on an oxide basis, of 58-64% SiO 2 , 16-19% Al 2 O 3 , greater than 6 and less than 13% B 2 O 3 , 5-11% CaO, 0-3% SrO, 0-3% BaO, 1-8% MgO, and SrO and BaO in combination being less than 3%. 
     
     
       14. A glass exhibiting a linear coefficient of thermal expansion (CTE) over the temperature range 0-300° C. between 30-40×10 −7 /° C. and a strain point over 600° C.  650 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of 58-70% SiO 2 , 12-22% Al 2 O 3 , 3 5-15% B 2 O 3 , 2 5-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, and SrO and BaO in combination being less than 3%, said glass containing in addition to CaO, at least one of MgO, SrO, and BaO. 
     
     
       15. A glass in accordance with  claim 14  which is manufactured by the float process, said glass having a liquidus viscosity greater than about  50 MPa·s Pa·s  (500 poises). 
     
     
       16. A glass according to  claim 14 , wherein said glass has a CTE of 32-38×10 −7 /° C. and a strain point over 650° C. 
     
     
       17. A glass according to  claim 16 , wherein said glass has a strain point over 675° C. 
     
     
       18. A photovoltaic device comprising a substrate in accordance with  claim 1 . 
     
     
       19. A substrate glass according to  claim 14 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-67% SiO 2 , 15-20% Al 2 O 3 , 5-13% B 2 O 3 , 5-12% CaO, 0-3% SrO, 0-3% BaO, 1-8% MgO, and SrO and BaO in combination is less than 3 wt %. 
     
     
       20. A substrate according to  claim 1 , wherein MgO+CaO+SrO+BaO is  10-25 greater than or equal to 10 and less than 23  weight percent. 
     
     
       21. A substrate according to  claim 1 , wherein MgO+CaO+SrO+BaO is 8.6-18.2 8.6-14.8 weight percent. 
     
     
       22. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point of  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  6 . 5 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       23. A glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  6 . 5 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, and SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       24. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       25. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, and SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       26. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  60 . 5 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO, SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       27. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  60 . 5 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO, and SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       28. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, SrO and BaO in combination being less than  3   %. 
     
     
       29. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, and SrO and BaO in combination being less than  3   %. 
     
     
       30. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  60 . 5 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO, SrO and BaO in combination being less than  3   %. 
     
     
       31. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  60 . 5 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO, and SrO and BaO in combination being less than  3   %. 
     
     
       32. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  6 . 5 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, SrO and BaO in combination being less than  3   %. 
     
     
       33. A glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  6 . 5 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, and SrO and BaO in combination being less than  3   %. 
     
     
       34. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  25 - 300 ° C. between  30 - 41 . 5 × 10     −7   /° C. and a strain point over  650 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  3 . 8 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       35. A glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  25 - 300 ° C. between  30 - 41 . 5 × 10     −7   /° C. and a strain point over  650 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  12 - 22   %  Al   2   O   3   ,  3 . 8 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, and SrO and BaO in combination being less than  3   % , said glass containing in addition to CaO, at least one of MgO, SrO, and BaO.   
     
     
       36. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  25 - 300 ° C. between  30 - 41 . 5 × 10     −7   /° C. and a strain point over  650 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  3 . 8 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, SrO and BaO in combination being less than  3   %. 
     
     
       37. A glass exhibiting a linear coefficient of thermal expansion ( CTE )  over the temperature range  25 - 300 ° C. between  30 - 41 . 5 × 10     −7   /° C. and a strain point over  650 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  15 - 18 . 9  Al   2   O   3   ,  3 . 8 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO, and SrO and BaO in combination being less than  3   %. 
     
     
       38. A substrate according to  claim 1  or  13 , wherein the glass has a density of less than  2 . 50  g/cm 3 . 
     
     
       39. A glass according to  claim 14 , wherein the glass has a density of less than  2 . 50  g/cm 3 . 
     
     
       40. A substrate according to  claim 1  or  13 , wherein the glass has a liquidus temperature below about  1250 ° C. 
     
     
       41. A glass according to  claim 14 , wherein the glass has a liquidus temperature below about  1250 ° C. 
     
     
       42. A substrate according to  claim 13 ,  22 ,  24 ,  26 ,  28 ,  30 ,  32 ,  48 ,  50 ,  52 , or  54  wherein the glass has a strain point over  650 ° C. 
     
     
       43. A glass according to  claim 23 ,  25 ,  27 ,  29 ,  31 ,  33 ,  49 ,  51 ,  53 , or  55  wherein the glass has a strain point over  650 ° C. 
     
     
       44. A substrate in accordance with  claim 1 ,  13 ,  22 ,  24 ,  26 ,  28 ,  30 ,  32 ,  34 ,  36 ,  48 ,  50 ,  52 , or  54  wherein the glass is manufactured by the float process. 
     
     
       45. A glass in accordance with  claim 14 ,  23 ,  25 ,  27 ,  29 ,  31 ,  33 ,  35 ,  37 ,  49 ,  51 ,  53 , or  55  which is manufactured by the float process. 
     
     
       46. A flat panel display comprising a substrate in accordance with  claim 13 ,  22 ,  24 ,  26 ,  28 ,  30 ,  32 ,  34 ,  36 ,  48 ,  50 ,  52 , or  54 . 
     
     
       47. A photovoltaic device comprising a substrate in accordance with  claim 13 ,  22 ,  24 ,  26 ,  28 ,  30 ,  32 ,  34 ,  36 ,  48 ,  50 ,  52 , or  54 . 
     
     
       48. A substrate for a flat panel display or photovoltaic device wherein sad substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO.   
     
     
       49. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO.   
     
     
       50. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of  60 . 5 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO.   
     
     
       51. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of  60 . 5 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO.   
     
     
       52. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis that comprises  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO.   
     
     
       53. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis that comprises  58 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 8   %  MgO.   
     
     
       54. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis that comprises  60 . 5 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO.   
     
     
       55. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion  ( CTE )  over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis that comprises  60 . 5 - 70   %  SiO   2   ,  15 - 18 . 9   %  Al   2   O   3   ,  7 . 1 - 15   %  B   2   O   3   ,  6 . 1 - 12   %  CaO,  0 - 1 . 9   %  SrO,  0 - 3   %  BaO,  0 - 6   %  MgO.   
     
     
       56. A substrate in accordance with  claim 1 ,  13 ,  22 ,  24 ,  26 ,  28 ,  30 ,  32 ,  34 ,  36 ,  48 ,  50 ,  52 , or  54  wherein the glass is essentially free of intentionally added alkali metal oxide. 
     
     
       57. A glass in accordance with  claim 14 ,  23 ,  25 ,  27 ,  29 ,  31 ,  33 ,  35 ,  37 ,  49 ,  51 ,  53 , or  55  wherein the glass is essentially free of intentionally added alkali metal oxide.