US5135894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particulate ceramics materials and production thereof
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1990-04-09
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Granted: 1992-08-04
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Expires: 2010-04-09
Abstract
Abstract A process for producing a dried particulate ceramic material in which a cake comprising a dispersion of at least 25% by volume of particulate ceramic material in a liquid medium is subjected to rapid drying. Also, a dried particulate ceramic material which may be dispersed in a liquid medium to form a dispersion containing at most only a small proportion of aggregates of the primary particles of the ceramic material.
Inventors
- 👤 Kevin Kendall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:50
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; B; B22; B22F; B22F1/00; B22F1/06; C01; C01B; C01B13/00; C01B13/14; C01B13/145; C01B21/00; C01B21/06; C01B21/0615; C01B21/0617; C01B21/062; C01B21/0632; C01B21/076
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
65 words
A process for producing a dried particulate ceramic material by drying a dispersion of particulate ceramic material in a liquid medium in which the dispersion which is dried is in the form of a cake containing at least 25% by volume of particulate ceramic material and the dried particulate ceramic material is produced by rapid drying of the cake to remove the liquid medium therefrom.
Claim 2
Dependent Claim
65 words
A process for producing a dried particulate ceramic material by drying a dispersion of particulate ceramic material in a liquid medium in which the dispersion which is dried is in the form of a cake containing at least 25% by volume of particulate ceramic material and the dried particulate ceramic material is produced by rapid drying of the cake to remove the liquid medium therefrom.
Claim 3
Dependent Claim
25 words
A process as claimed in claim 1 in which the cake is formed from a fluid dispersion of particulate ceramic material in a liquid medium.
Claim 4
Dependent Claim
22 words
A process as claimed in claim 2 in which the fluid dispersion contains at least 5% by volume of particulate ceramic material.
Claim 5
Dependent Claim
22 words
A process as claimed in claim 3 in which the fluid dispersion contains at least 10% by volume of particulate ceramic material.
Claim 6
Dependent Claim
43 words
A process as claimed in anyone of claims 2 to 4 in which the cake is formed by causing or allowing sedimentation of the fluid dispersion to take place and by removing the supernatent liquid from the cake which is formed by sedimentation.
Claim 7
Dependent Claim
48 words
A process as claimed in any one of claims 2 to 4 in which in a preliminary stage of the process the fluid dispersion is subjected to a preliminary sedimentation step and the resultant supernatent dispersion is separated from sedimented aggregates of the primary particles of the dispersion.
Claim 8
Dependent Claim
32 words
A process as claimed in any one of claims 2 to 4 in which the particulate ceramic material in the fluid dispersion has a primary particle size of less than 5 microns.
Claim 9
Dependent Claim
27 words
A process as claimed in claim 7 in which the particulate ceramic material in the fluid dispersion has a primary particle size of less than 1 micron.
Claim 10
Dependent Claim
19 words
A process as claimed in any one of claims 1 to 4 in which the liquid medium is water.
Claim 11
Dependent Claim
26 words
A process as claimed in any one of claims 1 to 4 in which the dispersion contains a dispersing agent in solution in the liquid medium.
Claim 12
Dependent Claim
21 words
A process as claimed in claim 5 in which sedimentation of the fluid dispersion is effected by centrifuging the fluid dispersion.
Claim 13
Dependent Claim
30 words
A process as claimed in any one of claims 1 to 4 in which the cake which is rapidly dried contains at least 40% by volume of particulate ceramic material.
Claim 14
Dependent Claim
35 words
A process as claimed in any one of claims 1 to 4 in which rapid drying of the cake is effected by subjecting the cake to microwave heating, to freeze drying, or to a vacuum.
References Cited (Backward Citations)
US4624808A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |