Patent US4840653A successfully refreshed from Google Patents.
US4840653A
Expired / Lapsed
US
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Fabrication of high-silica glass article
Assignee: Nokia Bell Labs
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Filing: 1988-09-19
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Granted: 1989-06-20
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Expires: 2008-09-19
Abstract
Abstract Incorporation of fluorine into a porous silica body, such as an unsintered body produced by a sol-gel method, by VAD or OVPO, reduces or eliminates bubble or pore formation upon re-heating of the glass formed by sintering of the porous material. Effective fluorine concentrations are between 0.01 and 5% by weight. The invention can be used advantageously in producing preforms and optical fiber.
Inventors
- 👤 Eliezer M. Rabinovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:30
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/14; C03B19/1453; C03B19/12; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/01446; C03B37/016; C03C; C03C1/00; C03C1/006; C03C3/00; C03C3/04; C03C3/06; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/12; C03B2201/14; C03C2201/00; C03C2201/06; C03C2201/08; C03C2201/12; C03C2201/14; C03C2203/00; C03C2203/20; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16; Y10S65/901
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
A method for fabricating an article comprising silica-containing glass, the method comprising the steps of: dispersing silica-containing material in a polar liquid to form a sol; gelling said sol to form a gel body; treating said gel body with heat to form a silica-containing glass body; and completing the fabrication of said article, Characterized In That said silica-containing material includes at least a first portion containing chemically bound fluorine and a second portion which is essentially free of chemically bound fluorine, the duration of said gelling step ranging from about 5 minutes to about 24 hours.
Claim 2
Independent Claim
96 words
A method for fabricating an article comprising silica-containing glass, the method comprising the steps of: dispersing silica-containing material in a polar liquid to form a sol; gelling said sol to form a gel body; treating said gel body with heat to form a silica-containing glass body; and completing the fabrication of said article, Characterized In That said silica-containing material includes at least a first portion containing chemically bound fluorine and a second portion which is essentially free of chemically bound fluorine, the duration of said gelling step ranging from about 5 minutes to about 24 hours.
Claim 3
Dependent Claim
58 words
The method of claim 1 further comprising the step of reacting at least a silicon-containing compound in a liquid state or in solution with a water-containing solution, with fluoride ions being present during at least a portion of the reaction between said compound and said water-containing solution, said reacting step leading to the formation of said first portion.
Claim 4
Dependent Claim
29 words
The method of claim 2 wherein the amount of said fluoride ions ranges from about 0.5 to about 40 grams of F per 100 grams of SiO 2 .
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein the amount of said first portion, as a percentage of the total of said first and second portions, ranges from about 3 percent by weight to about 60 percent by weight.
Claim 6
Dependent Claim
31 words
The method of claim 1 wherein the silica-containing material in said second portion has a BET surface area per unit mass less than or equal to about 100 m 2 /g.
Claim 7
Independent Claim
120 words
A method for fabricating an article comprising silicacontaining glass, the method comprising the steps of: dispersing silica-containing material in a polar liquid to form a sol; gelling said sol to form a gel body; treating said gel body with heat to form a silica-containing glass body; and completing the fabrication of said article, Characterized In That said silica-containing material includes at least a first portion containing chemically bound fluorine and a second portion which is essentially free of chemically bound fluorine, the amount of fluoride ion in said sol resulting from said dispersing step ranging from about 0.2 grams of F per 100 grams of SiO 2 to about 6 grams of F per 100 grams of SiO 2 .
Claim 8
Independent Claim
120 words
A method for fabricating an article comprising silicacontaining glass, the method comprising the steps of: dispersing silica-containing material in a polar liquid to form a sol; gelling said sol to form a gel body; treating said gel body with heat to form a silica-containing glass body; and completing the fabrication of said article, Characterized In That said silica-containing material includes at least a first portion containing chemically bound fluorine and a second portion which is essentially free of chemically bound fluorine, the amount of fluoride ion in said sol resulting from said dispersing step ranging from about 0.2 grams of F per 100 grams of SiO 2 to about 6 grams of F per 100 grams of SiO 2 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |