Patent US4417910A successfully refreshed from Google Patents.
US4417910A
Expired / Lapsed
US
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Process for manufacturing a glass tube comprising at least one doped silica layer
Assignee: Individual
•
Filing: 1981-09-14
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Granted: 1983-11-29
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Expires: 2001-09-14
Abstract
Abstract A process for manufacturing a glass tube, comprising at least one doped silica layer, wherein the layer is formed by forming a gel in situ, by the atomization of a hydrolyzing agent, onto a layer of a gelable liquid containing an alkoxy silane on a cylindrical mandrel rotated in a centrifuge, the gelable liquid and/or hydrolyzing agent containing a doping element, whereafter the resulting gel layer is subjected, after the withdrawal of the mandrel, to at least one thermal treatment to dry the gel and convert it into doped vitreous silica. The process can be applied to the production of preforms for the manufacture of optical fibers.
Inventors
- 👤 Michel Passaret
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:49
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/12; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/016; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16; Y10S65/901
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
126 words
A process for manufacturing a glass tube comprising at least one doped layer which process comprises the following steps: atomizing onto the inside surface of a cylindrical mandrel rotated in a centrifuge, a gelable liquid containing an alkoxysilane so as to form on the mandrel, a layer of said gelable liquid; simultaneously atomizing on said layer a hydrolyzing agent to convert the layer of gelable liquid to a layer of gel; with the hydrolyzing agent and/or the gelable liquid containing a doping element; withdrawing the mandrel from the centrifuge, with the layer of gel remaining in the centrifuge; and submitting the layer of gel thus obtained to at least one thermal treatment, to dry and thermally consolidate the layer into a tube of doped vitrious silica.
Claim 2
Dependent Claim
126 words
A process for manufacturing a glass tube comprising at least one doped layer which process comprises the following steps: atomizing onto the inside surface of a cylindrical mandrel rotated in a centrifuge, a gelable liquid containing an alkoxysilane so as to form on the mandrel, a layer of said gelable liquid; simultaneously atomizing on said layer a hydrolyzing agent to convert the layer of gelable liquid to a layer of gel; with the hydrolyzing agent and/or the gelable liquid containing a doping element; withdrawing the mandrel from the centrifuge, with the layer of gel remaining in the centrifuge; and submitting the layer of gel thus obtained to at least one thermal treatment, to dry and thermally consolidate the layer into a tube of doped vitrious silica.
Claim 3
Dependent Claim
19 words
The process according to claim 1, wherein the gelable liquid comprises a mixture of an alkoxysilane and an alkoxygermane.
Claim 4
Dependent Claim
20 words
The process according to claim 1, wherein the gelable liquid comprises a mixture of a fluorinated alkoxysilane and an alkoxysilane.
Claim 5
Dependent Claim
24 words
The process according to claim 2 or 3 wherein the hydrolyzing agent is an acidic aqueous solution having a pH substantially equal to 1.
Claim 6
Dependent Claim
24 words
The process according to claim 2 or 3, wherein the hydrolyzing agent is a basic aqueous solution having a pH substantially equal to 11.
Claim 7
Dependent Claim
24 words
The process according to claim 1, wherein the gelable liquid is an alkoxysilane, and the hydrolyzing agent is an aqueous solution containing fluoride ions.
Claim 8
Dependent Claim
21 words
The process according to claim 6, wherein the aqueous solution is an acidic solution having a pH substantially equal to 1.
Claim 9
Dependent Claim
21 words
The process according to claim 6, wherein the aqueous solution is a basic solution having a pH substantially equal to 11.
Claim 10
Dependent Claim
11 words
The process according to claim 2, wherein the alkoxysilane is tetraethoxysilane.
Claim 11
Dependent Claim
13 words
The process according to claim 3, wherein the fluorinated alkoxysilane is tetra (2-fluoroethoxysilane).
Claim 12
Dependent Claim
11 words
The process according to claim 2, wherein the alkoxygermane is tetraethoxygermane.
Claim 13
Dependent Claim
35 words
The process according to claim 1, wherein the composition of the gelable liquid and/or the hydrolyzing agent atomized onto the mandrel is varied continuously so as to form a gel layer whose composition varies radially.
Claim 14
Dependent Claim
38 words
The process according to claim 1, wherein the thermal treatment is performed in two stages, the first stage being performed at a temperature of 150°-200° C., and the second stage being performed at a temperature of 700°-1050° C.
Claim 15
Dependent Claim
18 words
The process according to claim 13, wherein the first stage of the thermal treatment is performed under centrifugation.
Claim 16
Dependent Claim
22 words
The process according to claim 13 or 14, wherein the second stage of the thermal treatment is performed in a dehydrating atmosphere.
Claim 17
Dependent Claim
15 words
The process according to claim 15, wherein the dehydrating atmosphere comprises chlorine or thionyl chloride.
Claim 18
Dependent Claim
50 words
A process for the production of a preform which can be used for the manufacture of optical fibers wherein a hollow glass tube comprising at least one doped silica layer is prepared by the process according to claim 1, the resulting hollow glass tube being subjected to a collapsing operation.
References Cited (Backward Citations)
US2268589A
Cited
US4242375A
Cited
US3853520A
Cited
US3853521A
Cited
US4217027A
Cited
US4217027B1
Cited
DE2447353A1
Cited
DE2545273A1
Cited
DE2638991A1
Cited
US4253863A
Cited
FR2429040B1
Cited
US4263032A
Cited
US4314837A
Cited
US4235616A
Cited
EP0025230A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-28 | 1987-05-30 | 1987-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-28 | 1991-05-30 | 1991-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-28 | 1995-05-30 | 1995-11-29 | $7700.00 | Window Closed / Lapsed |