US4120733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead-free glaze for alumina bodies
Assignee: Federal Mogul Ignition LLC
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Filing: 1977-12-01
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Granted: 1978-10-17
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Expires: 1997-12-01
Abstract
Abstract A high-silica ceramic glaze, having a low coefficient of thermal expansion, suitable for application to alumina bodies, is disclosed. The glaze consists essentially, by weight percent, of 48 to 54 percent SiO 2 , from 7 to 11 percent Al 2 O 3 , from 161/2 to 20 percent B 2 O 3 , from 11 to 14 percent BaO, from 2 to 3 percent CaO, from 2 to 21/2 percent ZnO, from 41/4 to 51/4 percent Na 2 O, and from 0.4 to 1 percent K 2 O. Li 2 O and MgO to the extent of up to about 1/4 percent and 1 percent, respectively, can also be tolerated, as can minor amounts of other impurities.
Inventors
- 👤 Randy O. Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:10
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/02; C03C8/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
A lead-free ceramic glaze for application to sintered high alumina substrates and maturing at temperatures from 1900° to 2200° F. consisting essentially of from 48 to 54 weight percent SiO 2 , from 7 to 11 percent Al 2 O 3 , from 161/2 to 20 percent B 2 O 3 , from 11 to 14 percent BaO, from 2 to 3 percent CaO, from 2 to 21/2 percent ZnO, from 41/4 to 51/4 percent Na 2 O, and from 0.4 to 1 percent K 2 O.
Claim 2
Dependent Claim
87 words
A lead-free ceramic glaze for application to sintered high alumina substrates and maturing at temperatures from 1900° to 2200° F. consisting essentially of from 48 to 54 weight percent SiO 2 , from 7 to 11 percent Al 2 O 3 , from 161/2 to 20 percent B 2 O 3 , from 11 to 14 percent BaO, from 2 to 3 percent CaO, from 2 to 21/2 percent ZnO, from 41/4 to 51/4 percent Na 2 O, and from 0.4 to 1 percent K 2 O.
Claim 3
Dependent Claim
57 words
A ceramic glaze as claimed in claim 1 consisting essentially of 50 percent SiO 2 , 81/2 percent Al 2 O 3 , 181/2 percent B 2 O 3 , percent CaO, 41/2 percent Na 2 O, 1/2 percent K 2 O, 1/4 percent Li 2 O, 2 percent ZnO, 123/4 percent BaO and 1/2 percent SrO.
Claim 4
Dependent Claim
41 words
A ceramic glazed as claimed in claim 1 wherein the normalized molecular formula contains from about 0.33 to 0.35 mole of R 2 O, about 0.1 mole of ZnO and from 1.37 to 1.54 moles of R 2 O 3 .
Claim 5
Dependent Claim
34 words
A ceramic glaze as claimed in claim 3 wherein from 1.07 to 1.14 moles of the R 2 O 3 in the normalized molecular formula for the glaze is B 2 O 3 .
Claim 6
Dependent Claim
23 words
A ceramic glaze as claimed in claim 4 wherein the RO in the normalized molecular formula is from substantially 0.54 to 0.57 mole.
Claim 7
Dependent Claim
27 words
A ceramic glaze as claimed in claim 5 wherein BaO constitutes from 0.31 to 0.36 mole of the RO in the normalized molecular formula for the glaze.
References Cited (Backward Citations)
US3640738A
Cited
US3927238A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |