US3923528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass-ceramic articles
Assignee: Nippon Sheet Glass Co Ltd
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Filing: 1974-03-22
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Granted: 1975-12-02
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Expires: 1994-03-22
Abstract
Abstract A glass-ceramic article, obtained by melting a glass composition comprising, on the weight percent basis, 54-68% SiO2, 5-13% Al2O3, 0-11% MgO, 8-28% CaO, the sum of the proportions of MgO and CaO being 18-28%, 2-8% B2O3, 0.1-2.5% ZnO, 0.05-0.3% sulfide sulfur, and 3-10% R2O, R2O being a combination of at least two of Li2O, Na2O and K2O, the mol ratio of LiO2/R2O being 0.05-0.4, the mol ratio of Na2O/R2O being 0-0.4, and the mol ratio of K2O/R2O being 0.5-0.95, the total of these components being at least 95% by weight, forming the molten glass into the desired shape, and heat-treating it.
Inventors
- 👤 Makoto Kume
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:16
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0036; C03C10/0045
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
93 words
A GLASS-CERAMIC ARTICLE CONSISTING ESSENTIALLY OF, ON A WEIGHT PERCENT BASIS, 54-68% SIO2, 5-13% AL2O3, 0-11% MGO, 8-28% CAO, THE SUM OF THE PROPORTIONS OF MGO AND CAO BEING 18-28%, 2-8% B2O3, 0.1-2.5% ZNO, 0.05-0.3% SULFIDE SULFUR, AND 3-10% R2O, R2O BEING A COMBINATION OF AT LEAST TWO OF LI2O, NA2O, AND K2O, THE MOL RATIO OF LI2O/R2O BEING 0.05-0.4, THE MOL RATIO OF NA2O/R2O BEING 0-0.4, AND THE MOL RATIO OF K2O/R2O BEING 0.5-0.95, THE TOTAL OF THESE COMPONENTS BEING AT LEAST 95% BY WEIGHT, SAID COMPOSITION BEING DEVOID OF FLUORINE THEREIN.
Claim 2
Dependent Claim
93 words
A GLASS-CERAMIC ARTICLE CONSISTING ESSENTIALLY OF, ON A WEIGHT PERCENT BASIS, 54-68% SIO2, 5-13% AL2O3, 0-11% MGO, 8-28% CAO, THE SUM OF THE PROPORTIONS OF MGO AND CAO BEING 18-28%, 2-8% B2O3, 0.1-2.5% ZNO, 0.05-0.3% SULFIDE SULFUR, AND 3-10% R2O, R2O BEING A COMBINATION OF AT LEAST TWO OF LI2O, NA2O, AND K2O, THE MOL RATIO OF LI2O/R2O BEING 0.05-0.4, THE MOL RATIO OF NA2O/R2O BEING 0-0.4, AND THE MOL RATIO OF K2O/R2O BEING 0.5-0.95, THE TOTAL OF THESE COMPONENTS BEING AT LEAST 95% BY WEIGHT, SAID COMPOSITION BEING DEVOID OF FLUORINE THEREIN.
Claim 3
Dependent Claim
18 words
The glass-ceramic article of claim 1 wherein the proportion of CaO is 15 to 28 % by weight.
Claim 4
Dependent Claim
18 words
The glass-ceramic article of claim 1 wherein the proportion of MgO is 0 to 3.5 % by weight.
Claim 5
Dependent Claim
17 words
The glass-ceramic article of claim 1 wherein the proportion of sulfide sulfur is 0.08 to 0.15 %.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |