US3653864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dealkalization of glass surfaces
Assignee: Corning Glass Works
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Filing: 1969-03-17
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Granted: 1972-04-04
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Expires: 1989-03-17
Abstract
Abstract This invention relates to the improvement in surface durability of alkali metal oxide containing glasses through the removal of the alkali metal oxide by a treatment which comprises hydrating the alkali metal oxide containing glass in an autoclave, and thereafter dealkalizing the glass surface by contacting it, at a moderate temperature, with a non-acidic non-aqueous solvent having a high dielectric constant. The resultant surface has substantially improved chemical surface durability.
Inventors
- 👤 Daphne L Rothermel
- 👤 Stanley D Stookey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:46
CPC Classifications
C; C03; C03C; C03C23/00; C03C21/00; C03C21/001
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
31 words
A method according to claim 1 wherein the period of time sufficient to provide a hydrated layer at least about 1 micron in depth ranges from about one-fourth - 16 hours.
Claim 2
Dependent Claim
28 words
A method according to claim 1 wherein the temperature at which the surface of the glass is contacted with the non-acidic, non-aqueous solvent ranges from about 90*-135* C.
Claim 3
Dependent Claim
29 words
A method according to claim 3 wherein the period of time sufficient to remove the alkali metal hydroxide hydration product from the hydrated layer ranges between about 10-15 minutes.
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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |