US4959347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forming homogeneous precursers of Bi-Sr-Ca-Cu via carboxylates in the presence of oxidizing agents
Assignee: Mitsubishi Electric Corp
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Filing: 1988-08-24
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Granted: 1990-09-25
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Expires: 2008-08-24
Abstract
Abstract A process for producing a superconductor of an oxide system, which comprises uniformly dissolving, dispersing or suspending in a solvent metal elements for constituting the oxide system at least partly in the form of carboxylates with the rest, if any, being in the form of alkoxides, acetylacetonates and/or inorganic compounds, followed by removal of the solvent to obtain a homogeneous mixture, and sintering the mixture.
Inventors
- 👤 Toshio Kobayashi
- 👤 Fusaoki Uchikawa
- 👤 Kenji Nomura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:00
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0772; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/734; Y10S505/735; Y10S505/775; Y10S505/776; Y10S505/782
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
93 words
A process for producing a superconductor of an oxide system containing metal elements in accordance with the formula: Bi.sub.1 Sr.sub.0.5-3 Ca.sub.0.5-3 Cu.sub.0.5-3.5 which process comprises: (a) uniformly dissolving, dispersing or suspending metal elements for constituting the oxide system in a solvent at least partly in the form of carboxylates, and in the presence of an oxidizing agent selected from the group consisting of hydrogen peroxide, benzoyl peroxide, peracetic acid, perbenzoic acid, ozone and m-chloroperbenzoic acid; and (b) removing the solvent to obtain a homogenous mixture, and sintering the mixture in an oxygen atmosphere.
Claim 2
Dependent Claim
93 words
A process for producing a superconductor of an oxide system containing metal elements in accordance with the formula: Bi.sub.1 Sr.sub.0.5-3 Ca.sub.0.5-3 Cu.sub.0.5-3.5 which process comprises: (a) uniformly dissolving, dispersing or suspending metal elements for constituting the oxide system in a solvent at least partly in the form of carboxylates, and in the presence of an oxidizing agent selected from the group consisting of hydrogen peroxide, benzoyl peroxide, peracetic acid, perbenzoic acid, ozone and m-chloroperbenzoic acid; and (b) removing the solvent to obtain a homogenous mixture, and sintering the mixture in an oxygen atmosphere.
Claim 3
Dependent Claim
17 words
The process according to claim 1, which further comprises presintering said mixture prior to sintering said mixture.
Claim 4
Dependent Claim
21 words
The process according to claim 1, wherein said sintering step is conducted in an atmosphere which is at least 50% oxygen.
Claim 5
Dependent Claim
19 words
The process according to claim 1, which further comprises subjecting said mixture, after sintering, to oxygen gas plasma treatment.
Claim 6
Dependent Claim
40 words
The process according to claim 1, wherein the remainder of said metal elements for constituting said oxide system are uniformly dissolved, dispersed or suspended in said solvent in the form of alkoxides, acetylacetonates or inorganic compounds or a combination thereof.
Claim 7
Dependent Claim
23 words
The process according to claim 1, wherein the uniformly dissolved, dispersed or suspended mixture is hydrolyzed prior to the removal of said solvent.
Claim 8
Dependent Claim
24 words
The process according to claim 1, wherein said solvent is used in an amount of about 10 times the total amount of the carboxylates.
Claim 9
Dependent Claim
16 words
The process according to claim 1, which further comprises effecting a presintering step prior to sintering.
Claim 10
Dependent Claim
17 words
The process according to claim 1, wherein said solvent is removed by the application of reduced pressure.
Claim 11
Dependent Claim
26 words
The process according to claim 2, wherein said sintering step comprises heating said mixture from about 850° to 1,000° C. for about 4 to 10 hours.
Claim 12
Dependent Claim
42 words
The process according to claim 4, wherein said oxygen gas plasma treatment is effected with an oxygen gas pressure of about 1 mb, using a power of about 30 to 100 W and for a time of from 0.5 to 3 hours.
Claim 13
Dependent Claim
20 words
The process according to claim 10, wherein said sintering step comprises heating said mixture from about 900° to 950° C.
References Cited (Backward Citations)
US4804649A
Cited
US4863521A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |