US4107388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the surface treatment of glass by leaching
Assignee: Industrie Zignago S Margherita SpA
•
Filing: 1977-02-09
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Granted: 1978-08-15
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Expires: 1997-02-09
Abstract
Abstract In the method for the removal of alkalies from glass surfaces and articles by reaction with hydrofluoric acid, the glass surface is contacted with a gas stream containing a compound of fluorine and silicium, preferably silicium tetrafluoride, and water in a predetermined ratio, the treatment being carried out at high temperature. Depending on the treatment conditions, a deposition of finely divided silica onto the glass surface under treatment can be obtained.
Inventors
- 👤 Gian Paolo Gambaretto
- 👤 Vittorio Gottardi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:54
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/22; C03C17/23; C03C17/245; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/213; C03C2218/00; C03C2218/10; C03C2218/15; C03C2218/152
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
56 words
A method of preparing a glass surface resistant to chemical attack which comprises contacting the glass surface with an air stream containing an equilibrium mixture of silicon tetrafluoride, silicon dioxide, hydrogen fluoride and water vapor at a temperature of from 400° to 700° C for a time sufficient to reduce the alkali content of said glass.
Claim 2
Independent Claim
56 words
A method of preparing a glass surface resistant to chemical attack which comprises contacting the glass surface with an air stream containing an equilibrium mixture of silicon tetrafluoride, silicon dioxide, hydrogen fluoride and water vapor at a temperature of from 400° to 700° C for a time sufficient to reduce the alkali content of said glass.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein said treatment is carried out at a temperature of 500°-600° C.
Claim 4
Dependent Claim
44 words
The method of claim 1 wherein the time of the treatment and the molar ratio SiF 4 /H 2 O in the gas stream are adjusted as a function of the possible desired deposition of finely divided silicon dioxide onto the surface under treatment.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein said air stream of treatment is generated by bubbling a carrier gas through a solution of fluorosilicic acid.
Claim 6
Dependent Claim
32 words
The method of claim 4, wherein said solution of fluorosilicic acid contains silica either in suspension or as a bottom body and is maintained at a temperature rectangular 20° to 110° C.
Claim 7
Dependent Claim
17 words
Glass surfaces and articles resistant to the chemical attack, prepared by the method of claim 1. having
Claim 8
Dependent Claim
19 words
Glass surfaces and articles coated with a deposit of finely divided silica, prepared by the method of claim 1.
References Cited (Backward Citations)
US2490662A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-14 | 1982-02-13 | 1982-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-14 | 1986-02-13 | 1986-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-14 | 1990-02-13 | 1990-08-15 | $7700.00 | Window Closed / Lapsed |