US3779856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass-ceramic and method for making same
Assignee: OI Glass Inc
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Filing: 1971-07-23
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Granted: 1973-12-18
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Expires: 1991-07-23
Abstract
Abstract High-strength glass-ceramics and a method of producing glassceramics having high strengths and good thermal shock resistance wherein a thermally crystallizable glass containing a nucleating agent capable of changing valency and which is more effective in the changed valency state is thermally in situ crystallized in a reducing atmosphere to form an at least partially crystalline glass-ceramic having a coefficient of thermal expansion which is considerably lower than that of the parent glass and having a high compressive stress layer on its surface.
Inventors
- 👤 P Pirooz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:30
CPC Classifications
B; B32; B32B; B32B17/00; B32B17/06; C; C03; C03B; C03B27/00; C03B27/012; C03B32/00; C03C; C03C10/00; C03C10/0018; C03C10/0027; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31; Y10T428/315
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
26 words
The transparent glass-ceramic body as defined in claim 1 wherein said CuO is present in an amount of from about 1 to about 3.5% by weight.
Claim 2
Dependent Claim
35 words
The glass-ceramic body as defined in claim 1 wherein the depth of said compressive stress layer is from about 100 to about 400 microns and the compressive stress is from about 20,000 to 80,000 psi.
Claim 3
Dependent Claim
28 words
The glass-ceramic body as defined in claim 3 wherein the difference in expansion coefficient between the glass and glass-ceramic bodies is at least 20 X 10 7/*C. (0*-300*C.).
Claim 4
Dependent Claim
142 words
A transparent glass-ceramic body having a compressive stress layer on its surface up to a depth of about 500 microns which compressive stress is at least 20,000 psi, and a coefficient of thermal expansion of + or - 12 X 10 7/*C. (0*-300*C.), said glass-ceramic body having a high quartz solid solution phase and formed by thermal in situ crystallization of a thermally crystallizable glass body having a coefficient of thermal expansion greater than that of said glass-ceramic, said glass body comprising at least 90 percent by weight of the following essential ingredients present in the indicated ranges: IngredientWeight Percent SiO257-69 Al2O320-31 Li2O3-6 Nucleating Agent3-10 CuO1-5 wherein the nucleating agent is selected from the group consisting of TiO2, ZrO2 and mixtures thereof, the SiO2/Al2O3 molar ratio is from 3.2 to 5.5 and the Li2O/Al2O3 molar ratio is from 0.4 to about 0.8.
Claim 5
Dependent Claim
35 words
The glass-ceramic body as defined in claim 5 wherein the depth of said compressive stress layer is from about 100 to about 400 microns and the compressive stress is from about 20,000 to 80,000 psi.
Claim 6
Dependent Claim
178 words
A transparent glass-ceramic body having a compressive stress layer on its surface and having a coefficient of thermal expansion of + or - 12 X 10 7/*C (0*-300*C), said glass ceramic body having a high quartz solid solution phase and formed by thermal in situ crystallization of a thermally crystallizable glass body having a coefficient of thermal expansion greater than that of said glass-ceramic, said glass body comprising at least 90 percent by weight of the following essential ingredients present in the indicated ranges: Ingredients Weight Percent SiO254-76 Al2O318-33 Li2O2-6.4 Nucleating Agent 3-8 Metal Oxide0.5-6 wherein said metal oxide is selected from the group consisting of copper oxide expressed as CuO and iron oxide expressed as Fe2O3 and the nucleating agent is selected from the group consisting of TiO2, ZrO2 and mixtures thereof, and when said agent is TiO2 or ZrO2 alone it is present in an amount of from 3 to 6 weight percent, the molar ratio of SiO2/Al2O3 is from 3 to 6 and the molar ratio of Li2O/Al2O3 is from about 0.3 to about 0.9.
Claim 7
Dependent Claim
14 words
A transparent glass-ceramic body of claim 7 wherein said metal oxide is iron oxide.
References Cited (Backward Citations)
US3231456A
Cited
US3464806A
Cited
US3490984A
Cited
US3486963A
Cited
US3637453A
Cited
US3582385A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |