US4940674A
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High strength, haze-free, transparent glass-ceramics
Assignee: Corning Inc
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Filing: 1989-11-13
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Granted: 1990-07-10
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Expires: 2009-11-13
Abstract
Abstract The present invention is directed to transparent, essentially haze-free glass-ceramic articles exhibiting moduli of rupture in excess of 10,000 psi which consist essentially, in weight percent, of 3-6% Li 2 O, 17-23% Al 2 O 3 , 1-4% B 2 O 3 , 60-70% SiO 2 , 3-6% TiO 2 and/or ZrO 2 , 25-500 ppm Cr 2 O 3 , and 1-5 mole percent of a glass modifying oxide selected from the group consisting of 0-3% K 2 O and 0-2.5% SrO and/or BaO.
Inventors
- 👤 George H. Beall
- 👤 Paul S. Danielson
- 👤 Robert M. Morena
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:25
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0054
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
122 words
Transparent glass-ceramic articles which display essentially no haze, which contain about 15-30% by volume of an aluminoborosilicate glass and β-quartz solid solution as essentially the sole crystal phase, and which exhibit moduli of rupture in the vicinity of 10,000 psi consisting essentially, expressed in terms of weight percent on the oxide basis, of 3-6% Li 2 O, 17-23% Al 2 O 3 , 1-4% B 2 O 3 , 60-70% SiO 2 , 3-6% TiO 2 and/or ZrO 2 , 25-500 ppm Cr 2 O 3 , and 1-5 mole percent of a glass modifying oxide selected from the group consisting of 0-3% K 2 O and 0.5-2.5% SrO and/or BaO with a molar ratio Al 2 O 3 :Li 2 O>1.
Claim 2
Dependent Claim
122 words
Transparent glass-ceramic articles which display essentially no haze, which contain about 15-30% by volume of an aluminoborosilicate glass and β-quartz solid solution as essentially the sole crystal phase, and which exhibit moduli of rupture in the vicinity of 10,000 psi consisting essentially, expressed in terms of weight percent on the oxide basis, of 3-6% Li 2 O, 17-23% Al 2 O 3 , 1-4% B 2 O 3 , 60-70% SiO 2 , 3-6% TiO 2 and/or ZrO 2 , 25-500 ppm Cr 2 O 3 , and 1-5 mole percent of a glass modifying oxide selected from the group consisting of 0-3% K 2 O and 0.5-2.5% SrO and/or BaO with a molar ratio Al 2 O 3 :Li 2 O>1.
Claim 3
Dependent Claim
22 words
Transparent glass-ceramic articles according to claim 1 wherein said Cr 2 O 3 is present in an amount between about 70-150 ppm.
Claim 4
Dependent Claim
34 words
Transparent glass-ceramic articles according to claim 1 wherein said K 2 O is present in an amount between about 1-3% by weight and BaO is present in an amount of about 0.5-2.5% by weight.
Claim 5
Dependent Claim
34 words
Transparent glass-ceramic articles according to claim 2 wherein said K 2 O is present in an amount between about 1-3% by weight and BaO is present in an amount of about 0.5-2.5% by weight.
Claim 6
Dependent Claim
132 words
Transparent glass-ceramic articles which display essentially no haze, which contain about 15-30% by volume of an aluminoborosilicate glass and β-quartz solid solution as essentially the sole crystal phase, which contain substantial residual compressive stresses in the outside surfaces thereof, and which exhibit moduli of rupture up to about 15,000 psi consisting essentially, expressed in terms of weight percent on the oxide basis, of 3-6% Li 2 O, 17-23% Al 2 O 3 , 1-4% B 2 O 3 , 60-70% SiO 2 , 3-6% TiO 2 and/or ZrO 2 , 25-500 ppm Cr 2 O 3 , and 1-5 mole percent of a glass modifying oxide selected from the group consisting of 0-3% K 2 O and 0.5-2.5% SrO and/or BaO with a molar ratio Al 2 O 3 :Li 2 O>1.
Claim 7
Dependent Claim
132 words
Transparent glass-ceramic articles which display essentially no haze, which contain about 15-30% by volume of an aluminoborosilicate glass and β-quartz solid solution as essentially the sole crystal phase, which contain substantial residual compressive stresses in the outside surfaces thereof, and which exhibit moduli of rupture up to about 15,000 psi consisting essentially, expressed in terms of weight percent on the oxide basis, of 3-6% Li 2 O, 17-23% Al 2 O 3 , 1-4% B 2 O 3 , 60-70% SiO 2 , 3-6% TiO 2 and/or ZrO 2 , 25-500 ppm Cr 2 O 3 , and 1-5 mole percent of a glass modifying oxide selected from the group consisting of 0-3% K 2 O and 0.5-2.5% SrO and/or BaO with a molar ratio Al 2 O 3 :Li 2 O>1.
Claim 8
Dependent Claim
22 words
Transparent glass-ceramic articles according to claim 5 wherein said Cr 2 O 3 is present in an amount between about 70-150 ppm.
Claim 9
Dependent Claim
34 words
Transparent glass-ceramic articles according to claim 5 wherein said K 2 O is present in an amount between about 1-3% by weight and BaO is present in an amount of about 0.5-2.5% by weight.
Claim 10
Dependent Claim
34 words
Transparent glass-ceramic articles according to claim 6 wherein said K 2 O is present in an amount between about 1-3% by weight and BaO is present in an amount of about 0.5-2.5% by weight.
References Cited (Backward Citations)
US4391914A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-07-09 | 1994-01-08 | 1994-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-09 | 1998-01-08 | 1998-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-09 | 2002-01-08 | 2002-07-10 | $7700.00 | Window Closed / Lapsed |