US4191583A
Expired / Lapsed
US
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Manganese cordierite glass-ceramics
Assignee: Corning Glass Works
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Filing: 1978-09-22
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Granted: 1980-03-04
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Expires: 1998-09-22
Abstract
Abstract Glass-ceramic products having a manganese-containing cordierite crystal structure and being impervious void free bodies exhibiting low coefficients of thermal expansions of ˜15×10 -7 /° C. (25°-1000° C.) and high electrical resistivity are obtained by the sintering of glass or glass-ceramic powders having the molar composition of about 2RO.2Al 2 O 3 .5SiO 2 , wherein RO is a combination of MgO and MnO.
Inventors
- 👤 William H. Armistead
- 👤 Irwin M. Lachman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:24
CPC Classifications
C; C03; C03C; C03C12/00; C03B; C03B19/00; C03B19/06; C03B32/00; C03B32/02; C03C10/00; C03C10/0036; C03C10/0045
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
39 words
An impervious sintered glass-ceramic product having a cordierite crystal structure and a composition within the range 1.7-2.4 RO.1.9-2.4 Al 2 O 3 .4.5-5.2 SiO 2 wherein RO comprises from 10-75 mole percent MgO and from 25-90 mole percent MnO.
Claim 2
Dependent Claim
39 words
An impervious sintered glass-ceramic product having a cordierite crystal structure and a composition within the range 1.7-2.4 RO.1.9-2.4 Al 2 O 3 .4.5-5.2 SiO 2 wherein RO comprises from 10-75 mole percent MgO and from 25-90 mole percent MnO.
Claim 3
Dependent Claim
20 words
An impervious sintered glass-ceramic product of claim 1 having the molar composition of 2RO.2Al 2 O 3 .5SiO 2 .
Claim 4
Dependent Claim
23 words
An impervious sintered glass-ceramic product of claim 2 wherein RO has the composition of 20-60 mole percent MgO and 40-80 mole percent MnO.
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) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |