Novel glass compositions
AssigneeNippon Electric Glass Co., Ltd.
InventorsNils Tryggve E. A. Baak, Charles F. Rapp
Life of this patent
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Abstract
Glass compositions of the SiO.sub.2 -ZrO.sub.2 -alkali metal oxide-alkaline earth oxide system containing 70-82 mole percent SiO.sub.2 and 2-8 mole percent ZrO.sub.2 and alkali metal oxides and alkaline earth oxides, and optionally Al.sub.2 O.sub.3, in specified amounts, such glasses being resistant to water, acids and alkalies, having a low to medium thermal coefficient of expansion and a low liquidus temperature.
Claims29
A glass composition consisting essentially of 75 to 82 mole percent SiO.sub.2, 2 to 8 mole percent ZrO.sub.2, 1 to 5 mole percent Al.sub.2 O.sub.3, 2 to 10 mole percent Na.sub.2 O, 2 to 10 mole percent K.sub.2 O, 2 to 10 mole percent CaO, 2 to 10 mole percent SrO, and 2 to 10 mole percent BaO, said composition being essentially free from boron.
A glass composition consisting essentially of 75 to 80 mole percent SiO.sub.2, 2 to 6 mole percent ZrO.sub.2, 1 to 3 mole percent Al.sub.2 O.sub.3, 0 to 6 mole percent Na.sub.2 O, 0 to 6 mole percent K.sub.2 O, 0 to 5 mole percent CaO, 0 to 5 mole percent SrO, and 0 to 5 mole percent BaO, and wherein the concentration of Na.sub.2 O and K.sub.2 O is 4 to 6 mole percent and wherein the concentration of CaO, BaO, and SrO is 8 to 12 mole percent, said composition being essentially free from boron.
A glass composition consisting essentially of
- ______________________________________ Ingredients Mole Percent ______________________________________ SiO.sub.2 70-82 ZrO.sub.2 2-8 Al.sub.2 O.sub.3 0-5 Na.sub.2 O 0-10 K.sub.2 O 0-10 CaO 0-15 SrO 0-15 BaO 0-15 MgO 0-15 (Na.sub.2 O + K.sub.2 O) 3-10 (CaO + SrO + BaO + MgO) 2-15 ______________________________________
- and wherein the concentration of (Na.sub.2 O + K.sub.2 O + CaO + SrO + BaO + MgO) is at least 12 mole percent, said composition being essentially free from boron.
A glass composition consisting essentially of
- ______________________________________ Ingredient Mole Percent ______________________________________ SiO.sub.2 75-82 ZrO.sub.2 2-8 Al.sub.2 O.sub.3 0-5 Na.sub.2 O 0-10 K.sub.2 O 0-10 Li.sub.2 O 0-10 CaO 0-15 SrO 0-15 BaO 0-15 MgO 0-15 (Na.sub.2 O + K.sub.2 O + Li.sub.2 O) 3-10 (CaO + SrO + BaO + MgO) 2-15 ______________________________________
- and wherein the concentration of (Na.sub.2 O + K.sub.2 O + Li.sub.2 O + CaO + SrO + BaO + MgO) is at least 10 mole percent and wherein said glass composition contains about 1 to 3 mole percent of a member selected from the group consisting of PbO, TiO.sub.2 and ZnO, and mixtures thereof, said composition being essentially free from boron.
A glass composition consisting essentially of 75 to 82 mole percent SiO.sub.2, 2 to 6 mole percent ZrO.sub.2, 1 to 3 mole percent A1.sub.2 O.sub.3, 0 to 6 mole percent Na.sub.2 O, 0 to 6 mole percent K.sub.2 O, 0 to 5 mole percent CaO, 0 to 5 mole percent SrO, 0 to 5 mole percent BaO, and wherein the concentration of Na.sub.2 O and K.sub.2 O is 4 to 6 mole percent and wherein the total concentration of CaO, BaO, and SrO is 8 to 12 mole percent, said composition being essentially free from boron.
A glass consisting essentially by mole percent on the oxide basis of about 0-10 mole percent Na.sub.2 O and/or 0-10 mole percent K.sub.2 O, the total of Na.sub.2 O plus K.sub.2 O constituting 3-10 mole percent, 70-82 mole percent SiO.sub.2, 2-15 mole percent strontium oxide, 2-8 mole percent ZrO.sub.2, said Na.sub.2 O and l or K.sub.2 0, SiO.sub.2 and SrO constituting at least about 74% by weight of the total composition.
A glass consisting essentially, by mole percent on the oxide basis, of about 70-82 mole percent SiO.sub.2, 0-10 mole percent Na.sub.2 O, O-10 mole percent K.sub.2 O, the total of K.sub.2 O + Na.sub.2 O constititing 3-10 mole percent, 2-15 mole percent SrO, and 2-8 mole percent ZrO.sub.2, said Na.sub.2 O + K.sub.2 O + SrO being at least 12 mole percent and the total of SiO.sub.2 + Na.sub.2 O + K.sub.2 O + SrO constituting at least 82 mole percent of the total glass composition.
A glass consisting essentially, by weight percent on the oxide basis, of about 65.2 to 76 percent SiO.sub.2, 0 to 5 percent Na.sub.2 O, 0 to 6.7 percent K.sub.2 O, the total of K.sub.2 O and Na.sub.2 O constituting from 4.4 to 6.7 percent, 3 to 15.3 percent SrO and 2.8 to 9.7 percent ZrO.sub.2.
Dependencies are inferred from the claim text.