US4889665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing ultrafine particles of ceramics
Assignee: National Institute for Materials Science
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Filing: 1986-07-07
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Granted: 1989-12-26
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Expires: 2006-07-07
Abstract
Abstract A process for producing ultrafine particles of a ceramic, which comprises heating a ceramic having substantially the same components as the final ultrafine ceramic particles, a metal constituting the metal component of the final ultrafine ceramic particles, a mixture of said ceramic with said metal or carbon, or a mixture of said metal with carbon by an arc plasma or a high frequency induction plasma generated in hydrogen, nitrogen, oxygen, a gaseous mixture of hydrogen and nitrogen, or a gaseous mixture of nitrogen and oxygen.
Inventors
- 👤 Masahiro Uda
- 👤 Satoru Ohno
- 👤 Hideo Okuyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:52
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; B; B01; B01J; B01J15/00; B01J19/00; B01J19/08; B01J19/087; B01J19/088; B82; B82Y; B82Y30/00; C01B13/00; C01B13/14; C01B13/32; C01B13/326; C01B21/00; C01B21/06; C01B21/072; C01B21/0722; C01B21/0724; C01B21/076; C01B21/0761; C01F; C01F11/00; C01F11/02; C01F5/00; C01F5/02; C01G; C01G25/00; C01G25/02; C01G37/00; C01G37/02; C01G39/00; C01G39/02; C01G41/00; C01G41/02; C01P; C01P2002/00; C01P2002/01; C01P2002/70; C01P2002/77; C01P2004/00; C01P2004/01; C01P2004/04; C01P2004/10; C01P2004/20; C01P2004/22; C01P2004/30; C01P2004/32; C01P2004/38; C01P2004/50; C01P2004/54; C01P2004/60; C01P2004/62; C01P2004/64
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
A process for producing ultrafine particles of ceramics selected from the group consisting of oxides of Ca, Mg, Zr, Cr, Mo and W and carbides of Si, Ti, Hf and W, which comprises (1) contacting a mass of ceramics selected from the group consisting of oxides of Ca, Mg, Zr, Cr, Mo and W and carbides of Si, Ti, Hf and W with a gas activated by an arc plasma which is generated by application of a voltage across a pair of discharging electrodes at a pressure of about 50 to 760 torr to generate ultrafine particles of said ceramic, wherein said gas is selected from the group consisting of nitrogen, oxygen, and a gaseous mixture of nitrogen and oxygen, and (2) cooling and collecting said particles.
Claim 2
Dependent Claim
127 words
A process for producing ultrafine particles of ceramics selected from the group consisting of oxides of Ca, Mg, Zr, Cr, Mo and W and carbides of Si, Ti, Hf and W, which comprises (1) contacting a mass of ceramics selected from the group consisting of oxides of Ca, Mg, Zr, Cr, Mo and W and carbides of Si, Ti, Hf and W with a gas activated by an arc plasma which is generated by application of a voltage across a pair of discharging electrodes at a pressure of about 50 to 760 torr to generate ultrafine particles of said ceramic, wherein said gas is selected from the group consisting of nitrogen, oxygen, and a gaseous mixture of nitrogen and oxygen, and (2) cooling and collecting said particles.
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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) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |