US3790430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkali aluminosilicate glass article having an ion-exchanged surface layer
Assignee: Corning Glass Works
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Filing: 1968-08-21
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Granted: 1974-02-05
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Expires: 1988-08-21
Abstract
Abstract This invention relates to the strengthening of glass articles through an ion exchange process wherein alkali metal ions in a surface of a glass article are replaced by larger monovalent metal ions. In carrying out the process, a surface of the glass article is contacted with a source of the larger monovalent ions at an elevated temperature below the strain point of the glass for a sufficient length of time to cause the replacement of small alkali metal ions in the glass surface with the larger monovalent metal ions to a depth of at least five microns, thereby inducing a surface compression layer of this depth on the article. This invention is specifically directed to alkali aluminosilicate glasses.
Inventors
- 👤 E Mochel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:32
CPC Classifications
C; C03; C03C; C03C23/00; C03C15/00; C03C21/00; C03C21/001; C03C21/002; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03C3/093; C03C3/102; C03C3/108; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/24992; Y10T428/31; Y10T428/315
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
27 words
An alkali aluminosilicate glass article according to claim 1 wherein said smaller alkali metal ions are lithium ions and said larger monovalent metal ions are sodium ions.
Claim 2
Dependent Claim
27 words
An alkali aluminosilicate glass article according to claim 1 wherein said smaller alkali metal ions are sodium ions and said larger monovalent metal ions are potassium ions.
Claim 3
Dependent Claim
176 words
An alkali aluminosilicate glass article exhibiting a modulus of rupture of at least 30,000 psi after being subjected to surface abrasion, said article containing ions of an alkali metal and of a monovalent metal of larger size selected from the group consisting of the alkali metals, copper, and silver and having a surface compressive stress layer of a depth of at least 5 microns, the concentration of the ions of a monovalent metal of larger size being greater in the surface layer than in the interior portion of the article and the concentration of the smaller alkali metal ions being greater in the interior portion of said article than in the surface layer thereof, said differences in concentration creating the compressive stress in the surface layer, the interior portion of said glass article having a composition consisting essentially, by weight on the oxide basis, of about 5-25 percent alkali metal oxide, 10-25 percent Al2O3, and SiO2, the total of alkali metal oxide, Al2O3, and SiO2 constituting at least 80 percent by weight of the glass composition.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |