Patent US3607172A successfully refreshed from Google Patents.
US3607172A
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US
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Tripotassium phosphate treatment for strengthening glass
Assignee: OI Glass Inc
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Filing: 1968-11-01
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Granted: 1971-09-21
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Expires: 1988-11-01
Abstract
Abstract Strengthening glass articles by spraying the same with a water solution of tripotassium phosphate (K3 PO4) at a temperature slightly below the strain point of the glass, then holding the glass at such temperature for a time period sufficient to provide exchange of potassium ions for sodium ions of the glass surface, the potassium ions being of larger atomic diameter than the sodium ions whereby a surface compressive stress is created.
Inventors
- 👤 James P Poole
- 👤 Herbert C Snyder
- 👤 Mark A Boschini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:05
CPC Classifications
C; C03; C03C; C03C21/00; C03C21/001; C03C21/002
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
32 words
The method of claim 1 wherein the tripotassium phosphate is deposited against the heated glass body in water solution, the temperature of the glass bodies being sufficient to rapidly evaporate the solution.
Claim 2
Dependent Claim
17 words
The method of claim 2 wherein the water solution contains at least 10 percent of tripotassium phosphate.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein the glass body is maintained at a temperature between 500* F. and 1,050* F. for approximately 20 minutes or longer.
Claim 4
Dependent Claim
22 words
The method of claim 2 wherein the aqueous tripotassium phosphate solution is sprayed on a heated glass body immediately after formation thereof.
Claim 5
Dependent Claim
23 words
The method of claim 5 wherein the elevated temperature for ion exchange reaction is provided in the annealing treatment of the glass body.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |