Patent US3720526A successfully refreshed from Google Patents.
US3720526A
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US
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Glass-ceramic body
Assignee: Corning Glass Works
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Filing: 1971-08-12
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Granted: 1973-03-13
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Expires: 1991-08-12
Abstract
Abstract This invention relates to the manufacture of dense, fine-grained glass-ceramic articles having compositions within the Na2O and/or K2O-Al2O3-SiO2 field which are nucleated with TiO2 and/or ZrO2 and/or SnO2 and wherein the principal crystal phase is a nepheline-type crystal, i.e., a nepheline and/or kaliophilite solid solution.
Inventors
- 👤 D Duke
- 👤 Dowell J Mac
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:44
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0018; C03C10/0054
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
151 words
A glass-ceramic body dimensionally stable up to 1,200* C. having a coefficient of thermal expansion between 90-150 X 10 7/* C. and consisting essentially of nepheline-type and/or kaliophilite-type crystals randomly, but uniformly, dispersed in a glassy matrix, said crystals being predominantly less than 1 micron in diameter, comprising at least 50 percent by weight of the body, and being formed through crystallization in situ from a glass body consisting essentially, by weight on the oxide basis, of 35-50 percent SiO2, 30-45 percent Al2O3, 15-26 percent R2O, wherein R2O consists of 0-22 percent Na2O and 0-26 percent K2O and wherein the mole ratio of Al2O3 to R2O is greater than 1, and at least one nucleating agent selected from the group consisting of about 5-15 percent TiO2, 1-5 percent ZrO2, and 2-8 percent SnO2, said glossy matrix consisting essentially of the uncrystallized portion of the glass after the crystallization of the crystals.
Claim 2
Dependent Claim
151 words
A glass-ceramic body dimensionally stable up to 1,200* C. having a coefficient of thermal expansion between 90-150 X 10 7/* C. and consisting essentially of nepheline-type and/or kaliophilite-type crystals randomly, but uniformly, dispersed in a glassy matrix, said crystals being predominantly less than 1 micron in diameter, comprising at least 50 percent by weight of the body, and being formed through crystallization in situ from a glass body consisting essentially, by weight on the oxide basis, of 35-50 percent SiO2, 30-45 percent Al2O3, 15-26 percent R2O, wherein R2O consists of 0-22 percent Na2O and 0-26 percent K2O and wherein the mole ratio of Al2O3 to R2O is greater than 1, and at least one nucleating agent selected from the group consisting of about 5-15 percent TiO2, 1-5 percent ZrO2, and 2-8 percent SnO2, said glossy matrix consisting essentially of the uncrystallized portion of the glass after the crystallization of the crystals.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |