US4631114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removing a surface layer from a metal fluoride glass
Assignee: Corning Netoptix Inc
•
Filing: 1986-03-12
•
Granted: 1986-12-23
•
Expires: 2006-03-12
Abstract
Abstract A method for removing a surface layer from a metal fluoride glass containing barium ions, particularly glass rods of the type used for manufacturing fibers for optical communications technology. A rapid, uniform and turbidity-free erosion of a disturbed outside layer of the starting glass is accomplished with an etchant solution in which a fluoride complexing agent or a barium complexing agent is dissolved. In particular, a rapid dissolving of a barium fluoro-zirconate glass is achievable with an etchant solution containing acidic Zr (IV) salts, whereby the risk of contaminating the so etched surface by the etchant solution does not exist.
Inventors
- 👤 Hartmut Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:49
CPC Classifications
C; C03; C03C; C03C15/00; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
118 words
A method for the removal of a surface layer from a metal fluoride glass of the type suitable for the manufacture of fibers for optical communications technology and which glass contains ions of at least one chemical element whose fluoride is difficultly water-soluble, said process comprising the step of contacting surface portions of said glass with an etchant solution for sufficient time to etch the surface portions of said glass, the etchant solution containing dissolved therein at least one material selected from the group consisting of (a) at least one fluoride complexing agent, (b) at least one complexing agent capable of complexing with the ions of said chemical element whose fluoride is difficultly water-soluble, and (c) mixtures thereof.
Claim 2
Independent Claim
118 words
A method for the removal of a surface layer from a metal fluoride glass of the type suitable for the manufacture of fibers for optical communications technology and which glass contains ions of at least one chemical element whose fluoride is difficultly water-soluble, said process comprising the step of contacting surface portions of said glass with an etchant solution for sufficient time to etch the surface portions of said glass, the etchant solution containing dissolved therein at least one material selected from the group consisting of (a) at least one fluoride complexing agent, (b) at least one complexing agent capable of complexing with the ions of said chemical element whose fluoride is difficultly water-soluble, and (c) mixtures thereof.
Claim 3
Dependent Claim
26 words
A method of claim 1 wherein said chemical element whose fluoride is difficultly water-soluble is selected from the group of elements comprising alkaline earths and lead.
Claim 4
Dependent Claim
18 words
A method of claim 2, wherein barium is selected as said chemical element whose fluoride is difficultly water-soluble.
Claim 5
Dependent Claim
30 words
A method of claim 1 wherein said etchant solution contains at least one said fluoride complexing agent and none of said complexing agent capable of complexing with said chemical element.
Claim 6
Dependent Claim
28 words
A method of claim 4 wherein said fluoride complexing agent is selected only from the group consisting of zirconium (IV) salts and titanium (IV) salts, and mixtures thereof.
Claim 7
Dependent Claim
21 words
A method of claim 5 wherein said fluoride complexing agent is selected only from the group consisting of zirconium (IV) salts.
Claim 8
Dependent Claim
15 words
The method of claim 4 wherein said metal fluoride glass is composed of a fluoro-zirconate.
Claim 9
Dependent Claim
13 words
A method of claim 4, wherein an excess of dissolved zirconium is present.
Claim 10
Dependent Claim
11 words
A method of claim 1, wherein said etchant solution is acidic.
Claim 11
Dependent Claim
12 words
A method of claim 7, wherein said etchant solution is weakly acidic.
Claim 12
Dependent Claim
12 words
A method of claim 7, wherein said etchant solution contains hydrochloric acid.
Claim 13
Dependent Claim
36 words
A method of claim 4, wherein said etchant solution contains 0.5 molar Zr 4+ and said solution is prepared by dissolving ZrOCl 2 .8H 2 O or ZrCl 4 in 5 weight % aqueous hydrochloric acid.
Claim 14
Dependent Claim
36 words
The method of claim 12 wherein a glass having the molar composition 57ZrF 4 .34BaF 2 .5LaF 3 .4AlF 3 is contacted with said etchant solution, thereby to etch off the surface layer on said glass.
Claim 15
Dependent Claim
16 words
The method of claim 1 wherein said glass is initially in the form of a rod.
Claim 16
Dependent Claim
42 words
The method of claim 1 wherein said glass is initially in the form of a tube of the type adapted for employment in a MCVD process wherein said tube is collapsed after the inside surfaces of said tube have been so contacted.
References Cited (Backward Citations)
US3446682A
Cited
US3930870A
Cited
US4049413A
Cited
JPS5529020A
Cited
GB2071080A
Cited
US4445755A
Cited
JPS57166336A
Cited
GB2122599A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |