Patent US4539033A successfully refreshed from Google Patents.
US4539033A
Expired / Lapsed
US
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Method for drying oxide glasses
Assignee: British Telecommunications PLC
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Filing: 1983-09-08
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Granted: 1985-09-03
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Expires: 2003-09-08
Abstract
Abstract An oxide glass is dried by passing through a melt of the glass fluorine or another perhalogenated compound including fluorine atoms. For example, C3F8 (e.g. after pre-cracking) can be used to reduce the OH content of a borosilicate glass, and the loss of an optical fibre drawn from such a glass, to low levels.
Inventors
- 👤 Keith J. Beales
- 👤 Steve F. Carter
- 👤 Sally Partington
- 👤 Paul W. France
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:11
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/04; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/022; C03B37/023; C03B5/00; C03B5/16; C03B5/225; C03C3/00; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16; Y10S65/90
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A method for drying an oxide glass, and thereby reducing the water content of the glass, which comprises providing glass in a molten state, and passing a drying gas through the glass while it is in the molten state, in which the drying gas is of a perhalogenated compound containing only halogen and non-halogen atoms, where the non-halogen atoms are either carbon or sulphur, and at least some of the halogen atoms in the perhalogenated compound are fluorine.
Claim 2
Independent Claim
78 words
A method for drying an oxide glass, and thereby reducing the water content of the glass, which comprises providing glass in a molten state, and passing a drying gas through the glass while it is in the molten state, in which the drying gas is of a perhalogenated compound containing only halogen and non-halogen atoms, where the non-halogen atoms are either carbon or sulphur, and at least some of the halogen atoms in the perhalogenated compound are fluorine.
Claim 3
Dependent Claim
39 words
A method according to claim 1, in which a perhalogenated compound including fluorine atoms is heated, prior to introduction into the molten glass, to reduce the amount of components in the gas which may be retained in the glass.
Claim 4
Dependent Claim
18 words
A method according to claim 1, in which the halogen atoms are selected only from fluorine and chlorine.
Claim 5
Dependent Claim
12 words
A method according to claim 3, in which the compound is perfluorinated.
Claim 6
Dependent Claim
13 words
A method according to claim 2, in which the compound is a perhalocarbon.
Claim 7
Dependent Claim
13 words
A method according to claim 5, in which the compound is a perfluorocarbon.
Claim 8
Dependent Claim
16 words
A method according to claim 6, in which the perfluorocarbon is C 3 F 8 .
Claim 9
Dependent Claim
34 words
A method according to claim 1, in which a gas selected from CO and CO 2 is passed through the molten glass at the same time as, or prior to, the said perhalogenated compound.
Claim 10
Dependent Claim
22 words
A method according to claim 1, in which O 2 is passed through the molten glass prior to the said perhalogenated compound.
Claim 11
Dependent Claim
18 words
A method according to claim 1, in which the glass is a borosilicate for use in optical fibres.
Claim 12
Dependent Claim
67 words
A process for drying borosillicate glass, and thereby reducing the water content of the glass, which comprises providing glass in a molten state, and passing a drying gas through the glass while it is in the molten state, in which the drying gas is as of a perfluorinated compound selected from SF 6 and fluorocarbons having only carbon and fluorine atoms and having 1 to 5 atoms.
Claim 13
Dependent Claim
67 words
A process for drying borosillicate glass, and thereby reducing the water content of the glass, which comprises providing glass in a molten state, and passing a drying gas through the glass while it is in the molten state, in which the drying gas is as of a perfluorinated compound selected from SF 6 and fluorocarbons having only carbon and fluorine atoms and having 1 to 5 atoms.
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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) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |