Patent US3630704A successfully refreshed from Google Patents.
US3630704A
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Method for strengthening glass articles
Assignee: Corning Glass Works
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Filing: 1969-03-10
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Granted: 1971-12-28
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Expires: 1989-03-10
Abstract
Abstract This invention relates to the production of chemically strengthened sodium and/or potassium silicate glass articles utilizing a consecutive ion exchange reaction involving ion exchange media containing lithium ions. In carrying out the process of the invention, a surface of the glass article is first contacted with an external source of lithium ions at a temperature above the strain point of the glass but below the softening point thereof and, thereafter, this surface is contacted with an external source of lithium ions at a temperature above 200* C. but below the strain point of the glass.
Inventors
- 👤 Harmon M Garfinkel
- 👤 Joseph S Olcott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:46
CPC Classifications
C; C03; C03C; C03C21/00; C03C21/001; C03C21/002
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
30 words
A method according to claim 1 wherein said glass article consists essentially, by weight on the oxide basis, of about 5-25% Na2O and/or K2O, 5-25% Al2O3 and/or ZrO2 and SiO2.
Claim 2
Dependent Claim
35 words
A method according to claim 1 wherein the time sufficient to permit lithium ions to diffuse into the glass surface in exchange for sodium and/or potassium ions of the glass ranges between about 1-30 minutes.
Claim 3
Dependent Claim
45 words
A method according to claim 1 wherein the time sufficient to cause an exchange to occur between sodium and/or potassium ions from the inner portion of the glass article and the lithium ions introduced in the first exchange ranges between about one-half to 8 hours.
Claim 4
Dependent Claim
120 words
A method for strengthening sodium and/or potassium silicate glass article according to claim 1 wherein, after said article has been contacted with a source of lithium ions at a temperature above the strain point of said glass but below the softening point thereof and then contacted with a source of lithium ions at a temperature of at least 200* C. but below the strain point of the glass, said glass article is contacted with a source of sodium and/or potassium ions at a temperature of at least 200* C. but below the strain point of the glass for a time sufficient to cause an exchange to occur between lithium ions in the glass surface and said sodium and/or potassium ions.
Claim 5
Dependent Claim
30 words
A method according to claim 5 wherein said glass article consists essentially, by weight on the oxide basis, of about 5-25% Na2O and/or K2O, 5-25% Al2O3 and/or ZrO2, and SiO2.
Claim 6
Dependent Claim
36 words
A method according to claim 5 wherein the time sufficient to cause an exchange to occur between lithium ions in the glass surface and said sodium and/or potassium ions ranges between about one-half to 8 hours.
References Cited (Backward Citations)
US3287201A
Cited
US3395998A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |