Barium aluminosilicate glasses
First Claim
1. A glass exhibiting a strain point higher than 660°
- C., a liquidus temperature no higher than 1,175°
C., a weight loss of less than 1 mg/cm2 after immersion for 24 hours in an aqueous 5% by weight HCl solution at 95°
C., and long term stability against devitrification at melting and forming temperatures, said glass being essentially free from alkali metal oxides and consisting essentially, expressed in terms of mole percent on the oxide basis, of
space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 65-76 MgO 0-5 Al.sub.2 O.sub.3 7-11 CaO 0-10 TiO.sub.2 0-3 BaO 12-19 SrO 0-10 Ta.sub.2 O.sub.5 0-3 B.sub.2 O.sub.3 0-5 MgO + 0-15 TiO.sub.2 + 0.5-5. CaO + Ta.sub.2 O.sub.5 SrO ______________________________________
1 Assignment
0 Petitions
Accused Products
Abstract
This invention is directed to glass compositions particularly designed for use as substrates in flat panel display devices and, more expressly, for use as substrates in LCDs which employ polycrystalline silicon thin film transistors. The glass compositions are essentially free from alkali metal oxides and consist essentially, in mole percent, of
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SiO2 65-76 MgO 0-5 ZrO2 0-2.5 Al2 O3 7-11 CaO 0-10 TiO2 0-3 BaO 12-19 SrO 0-10 Ta2 O5 0-3 B2 O3 0-5 MgO + 0-15 ZrO2 + 0.5-5. CaO + TiO2 + SrO Ta2 O5 ______________________________________
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Citations
4 Claims
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1. A glass exhibiting a strain point higher than 660°
- C., a liquidus temperature no higher than 1,175°
C., a weight loss of less than 1 mg/cm2 after immersion for 24 hours in an aqueous 5% by weight HCl solution at 95°
C., and long term stability against devitrification at melting and forming temperatures, said glass being essentially free from alkali metal oxides and consisting essentially, expressed in terms of mole percent on the oxide basis, of
space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 65-76 MgO 0-5 Al.sub.2 O.sub.3 7-11 CaO 0-10 TiO.sub.2 0-3 BaO 12-19 SrO 0-10 Ta.sub.2 O.sub.5 0-3 B.sub.2 O.sub.3 0-5 MgO + 0-15 TiO.sub.2 + 0.5-5. CaO + Ta.sub.2 O.sub.5 SrO ______________________________________ - View Dependent Claims (2)
- C., a liquidus temperature no higher than 1,175°
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3. In a liquid crystal display device which employs polycrystalline silicon thin film transistors as switches, which device contains a flat, transparent glass substrate, the improvement wherein said glass exhibits a strain point higher than 660°
- C., a liquidus temperature no higher than 1,175°
C., a weight loss of less than 1 mg/cm2 after immersion for 24 hours in an aqueous 5% by weight HCl solution at 95°
C., and long term stability against devitrification at melting and forming temperatures, said glass being essentially free from alkali metal oxides and consisting essentially, expressed in terms of mole percent on the oxide basis, of
space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 65-76 MgO 0-5 Al.sub.2 O.sub.3 7-11 CaO 0-10 TiO.sub.2 0-3 BaO 12-19 SrO 0-10 Ta.sub.2 O.sub.5 0-3 B.sub.2 O.sub.3 0-5 MgO + 0-15 TiO.sub.2 + 0.5-5. CaO + Ta.sub.2 O.sub.5 SrO ______________________________________ - View Dependent Claims (4)
- C., a liquidus temperature no higher than 1,175°
Specification