Patent US4597786A successfully refreshed from Google Patents.
US4597786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purifying process of fluoride glass
Assignee: KDDI Corp
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Filing: 1985-08-19
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Granted: 1986-07-01
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Expires: 2005-08-19
Abstract
Abstract A fluoride glass for infrared optical transmission fiber is purified for dehydration and deoxidation to reduce transmission loss by reacting melted fluoride glass with NF 3 gas at temperature between 500° C. and 800° C. No scattering loss is increased by the present purification as decomposed product in the reaction does not precipitate.
Inventors
- 👤 Tetsuya Nakai
- 👤 Yoshinori Mimura
- 👤 Osamu Shinbori
- 👤 Hideharu Tokiwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:37
CPC Classifications
C; C01; C01G; C01G27/00; C01G27/04; C01G1/00; C01G1/06; C03; C03C; C03C3/00; C03C3/32; C03C3/325; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
58 words
A purifying process for dehydration and deoxidation of fluoride glass comprising the step of heating fluoride glass to temperature between 500° C. and 800° C. to melt the glass in atmosphere of fluoride nitrogen (NF 3 ) to react radical fluorine atom dissociated from NF 3 with hydroxyl group, complex ion and oxide included in the fluoride glass.
Claim 2
Dependent Claim
58 words
A purifying process for dehydration and deoxidation of fluoride glass comprising the step of heating fluoride glass to temperature between 500° C. and 800° C. to melt the glass in atmosphere of fluoride nitrogen (NF 3 ) to react radical fluorine atom dissociated from NF 3 with hydroxyl group, complex ion and oxide included in the fluoride glass.
Claim 3
Dependent Claim
68 words
A purifying process for dehydration and deoxidation of fluoride glass comprising the steps of; heating fluoride glass around 800° C. for at least 30 minutes to melt that fluoride glass, decreasing the temperature to around 700° C., flowing gas including NF 3 on melted fluoride glass by rate of about 3 liter/minute for at least 30 minutes, and cooling the fluoride glass by rate of about 30° C./minutes.
Claim 4
Dependent Claim
68 words
A purifying process for dehydration and deoxidation of fluoride glass comprising the steps of; heating fluoride glass around 800° C. for at least 30 minutes to melt that fluoride glass, decreasing the temperature to around 700° C., flowing gas including NF 3 on melted fluoride glass by rate of about 3 liter/minute for at least 30 minutes, and cooling the fluoride glass by rate of about 30° C./minutes.
Claim 5
Dependent Claim
30 words
A purifying process according to claim 1, wherein said gas including NF 3 is mixture of NF 3 and inert gas with mol-ratio of NF 3 between 1% and 10%.
Claim 6
Dependent Claim
18 words
A purifying process according to claim 1, wherein said gas including NF 3 is 10%NF 3 +90%Ar (mol%).
Claim 7
Dependent Claim
17 words
A purifying process according to claim 1, wherein said fluoride glass system is; ZrF.sub.4 --BaF.sub.2 --NaF--LaF.sub.3 --AlF.sub.3.
Claim 8
Dependent Claim
18 words
A purifying process according to claim 1, wherein said fluoride glass is H f H 4 group glass.
Claim 9
Dependent Claim
18 words
A purifying process according to claim 1, wherein said fluoride glass is used as an optical transmission fiber.
Claim 10
Dependent Claim
25 words
A purifying process according to claim 1, wherein fluoride glass which is subject to purification is pre-dried by flowing dry Ar gas on the glass.
Claim 11
Dependent Claim
36 words
A purifying process according to claim 1, wherein said complex ion includes at least one of NH 4 + , SO 4 -- , COOH - , CO 3 - , and NO 3 - .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-30 | 1989-12-30 | 1990-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-30 | 1993-12-30 | 1994-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-30 | 1997-12-30 | 1998-07-01 | $7700.00 | Window Closed / Lapsed |