US3697242A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Strengthening borosilicate glass by crowding surface layer with lioh and/or koh
Assignee: Anchor Hocking LLC
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Filing: 1969-03-13
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Granted: 1972-10-10
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Expires: 1989-03-13
Abstract
Abstract GLASS ARTICLES ARE STRENGHTENED BY "CROWDING" OR "STUFFING" MOLECULES OF THE HYDROXIDE OF LITHIUM AND/OR POTASSIUM INTO A SURFACE ZONE OF THE GLASS NETWORK. THE CROWDING OF THE SURFACE ZONE IS ACCOMPLISHED BY MOLECULAR MIGRATION RATHER THAN BY ION EXCHANGE, AND MUST BE CARRIED OUT AT AN ELEVATED TEMPERATURE WHICH IS BELOW THE STRAIN POINT OF THE GLASS. THE PROCESS IS ESPECIALLY USEFUL AS A MEANS OF STRENGTHENING COMMERCIAL BOROSILICATE GLASSES WHICH ARE GENERALLY DIFFICULT TO STRENGHTEN SIGNIFICANTLY BY ION EXCHANGE, AND IT CAN ALSO BE USED TO STRENGHTEN SODA-LIME AND OTHER GLASSES.
Inventors
- 👤 Francis J Shonebarger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:32
CPC Classifications
C; C03; C03C; C03C21/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |