US5196180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic powders
Assignee: Tioxide Specialties Ltd
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Filing: 1989-10-03
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Granted: 1993-03-23
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Expires: 2009-10-03
Abstract
Abstract A process for preparing ceramic powders suitable for pressing into articles comprises the dispersing of a particulate ceramic, preferably of particle size below 1 μm, in water in the presence of ammonia or an alkylamine having a boiling point below that of water and spray - drying the dispersion to give powders. The process is particularly applicable to zirconia and gives rise to fine, free-flowing powders which can be processed into articles of uniform density.
Inventors
- 👤 Angus J. Hartshorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:11
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; C09; C09K; C09K23/00; C01; C01B; C01B13/00; C01B13/14; C01B13/145; C04B35/622; C04B35/626
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
59 words
A process of preparing a ceramic powder suitable for pressing into articles by the steps of (a) dispersing a particulate ceramic in water in the presence of ammonia or an alkylamine having a boiling point below that of water, present in a quantity sufficient to disperse the ceramic; and (b) spray-drying the resulting dispersion to give a ceramic powder.
Claim 2
Dependent Claim
59 words
A process of preparing a ceramic powder suitable for pressing into articles by the steps of (a) dispersing a particulate ceramic in water in the presence of ammonia or an alkylamine having a boiling point below that of water, present in a quantity sufficient to disperse the ceramic; and (b) spray-drying the resulting dispersion to give a ceramic powder.
Claim 3
Dependent Claim
18 words
A process according to claim 1, wherein the particulate ceramic has a particle size of 1 um maximum.
References Cited (Backward Citations)
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US4540677A
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US4713233A
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US4746468A
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US4769351A
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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) | 1996-03-22 | 1996-09-21 | 1997-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-22 | 2000-09-21 | 2001-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-22 | 2004-09-21 | 2005-03-23 | $7700.00 | Window Closed / Lapsed |