Patent US2274697A successfully refreshed from Google Patents.
Patent US4097296A successfully refreshed from Google Patents.
US4097296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-temperature devitrifiable sealing composition
Assignee: Corning Glass Works
•
Filing: 1977-03-28
•
Granted: 1978-06-27
•
Expires: 1997-03-28
Abstract
Abstract A devitrifiable sealing composition which provides a strong devitrified seal with color television picture tube glass at reduced sealing temperatures, and which is thermally compatible with such glass during sealing and subsequent tube processing, is described.
Inventors
- 👤 Walter B. Thomas, III
- 👤 Christopher H. Welker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:03
CPC Classifications
C; C03; C03C; C03C27/00; C03C10/00; C03C10/0054; C03C8/00; C03C8/24; C03C8/245
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
152 words
A low-temperature devitrifiable sealing composition compatible with color television picture tube glass, said composition consisting of a zircon component and a devitrifiable glass component and including 2-6 parts zircon by weight for each 100 parts of devitrifiable glass by weight, wherein the devitrifiable glass component has a composition consisting essentially, in parts by weight, of about: 77.4 ± 2.0 parts PbO 10.2 ± 1.0 parts ZnO 8.9 ± 1.0 parts B 2 O 3 2.6 ± 0.25 parts SiO 2 0.17 ± 0.10 parts MgO 0.22 ± 0.10 parts BaO, and 0.35 ± 0.10 parts F said sealing composition exhibiting a sealing temperature of about 410°-425° C. and providing a devitrified seal having a thermal expansion mismatch value against 98 expansion color television glass which is within the range of -125 to 0 ppm at room temperature and does not change more than about 40 p.p.m. over the 350°-200° C. temperature range.
Claim 2
Dependent Claim
152 words
A low-temperature devitrifiable sealing composition compatible with color television picture tube glass, said composition consisting of a zircon component and a devitrifiable glass component and including 2-6 parts zircon by weight for each 100 parts of devitrifiable glass by weight, wherein the devitrifiable glass component has a composition consisting essentially, in parts by weight, of about: 77.4 ± 2.0 parts PbO 10.2 ± 1.0 parts ZnO 8.9 ± 1.0 parts B 2 O 3 2.6 ± 0.25 parts SiO 2 0.17 ± 0.10 parts MgO 0.22 ± 0.10 parts BaO, and 0.35 ± 0.10 parts F said sealing composition exhibiting a sealing temperature of about 410°-425° C. and providing a devitrified seal having a thermal expansion mismatch value against 98 expansion color television glass which is within the range of -125 to 0 ppm at room temperature and does not change more than about 40 p.p.m. over the 350°-200° C. temperature range.
Claim 3
Dependent Claim
47 words
A low-temperature devitrifiable sealing composition in accordance with claim 1 wherein the zircon component is within the range of 2-5 parts by weight for each 100 parts of devitrifiable glass, and wherein the devitrifiable glass component has a composition consisting essentially, in parts by weight, of about:
Claim 4
Dependent Claim
67 words
4 ± 0.2 parts PbO 10.2 ± 0.2 parts ZnO 8.9 ± 0.2 parts B 2 O 3 2.6 ± 0.1 parts SiO 2 0.17 ± 0.03 parts MgO 0.22 ± 0.05 parts BaO, and 0.35 ± 0.05 parts F said composition exhibiting a sealing temperature of about 415° C. and providing a devitrified seal having a modulus of rupture strength of about 6500 ± 500 psi.
Claim 5
Dependent Claim
67 words
4 ± 0.2 parts PbO 10.2 ± 0.2 parts ZnO 8.9 ± 0.2 parts B 2 O 3 2.6 ± 0.1 parts SiO 2 0.17 ± 0.03 parts MgO 0.22 ± 0.05 parts BaO, and 0.35 ± 0.05 parts F said composition exhibiting a sealing temperature of about 415° C. and providing a devitrified seal having a modulus of rupture strength of about 6500 ± 500 psi.
References Cited (Backward Citations)
US3258350A
Cited
US3951669A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |