US4699732A
Expired / Lapsed
US
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Preparation of dispersible cerium compound
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1985-11-20
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Granted: 1987-10-13
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Expires: 2005-11-20
Abstract
Abstract The invention provides a process for the preparation of a dispersible cerium compound (i.e. a cerium compound which may be dispersed in a liquid to give a colloidal dispersion (i.e. a sol)). The process involves replacing a first species of ions associated with the cerium compound by a second species of ions (e.g. hydroxyl ions) and subsequently replacing the second species of ions of the cerium compound with a third species of ions (e.g. counter-ions). The replacing of the ions may be effected, for example, by ion-exchange. Cerium (IV) oxide hydrate is an example of a cerium compound which can be made dispersible in accordance with the invention.
Inventors
- 👤 James L. Woodhead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:03
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/20; C01F17/276; C01F17/206; C01F17/224; C01F17/235; C01P; C01P2006/00; C01P2006/22; Y; Y10; Y10S; Y10S423/00; Y10S423/09; Y10S423/14
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
55 words
A process for the preparation of dispersible cerium compound which comprises replacing a first species of ions associated with a cerium compound by a second species of ions by ion-exchange and subsequently replacing the second species of ions of the chemical compound by a third species of ions, thereby to produce a dispersible cerium compound.
Claim 2
Dependent Claim
55 words
A process for the preparation of dispersible cerium compound which comprises replacing a first species of ions associated with a cerium compound by a second species of ions by ion-exchange and subsequently replacing the second species of ions of the chemical compound by a third species of ions, thereby to produce a dispersible cerium compound.
Claim 3
Dependent Claim
16 words
A process as claimed in claim 1 wherein the second species of ions comprises hydroxyl ions.
Claim 4
Dependent Claim
24 words
A process as claimed in claim 1 wherein replacement of the second species of ions by the third species of ions is by ion-exchange.
Claim 5
Dependent Claim
16 words
A process as claimed in claim 1 wheein the cerium compound is cerium (IV) oxide hydrate.
Claim 6
Dependent Claim
47 words
A process as claimed in claim 1 wherein cerium (IV) oxide hydrate is treated by ion exchange to replace nitrate ions associated with the hydrate with hydroxyl ions and subsequently hydroxyl groups on the hydrate are replaced by counter-ions to give a dispersible cerium (IV) oxide hydrate.
Claim 7
Dependent Claim
41 words
A process as claimed in claim 5 wherein cerium (IV) oxide hydrate is treated by ion exchange to ion-exchange nitrate ions associated with the hydrate with hydroxyl ions and subsequently counter-ions are introduced by ion-exchange with hydroxyl groups on the hydrate.
Claim 8
Dependent Claim
13 words
A process as claimed in claim 5 wherein the counter-ions are nitrate ions.
Claim 9
Dependent Claim
17 words
A process as claimed in claim 5 wherein counter-ions are provided from an acid or a salt.
Claim 10
Dependent Claim
17 words
A process as claimed in claim 1 wherein a further cation is introduced to the cerium compound.
Claim 11
Dependent Claim
20 words
A process as claimed in claim 9 wherein a metal salt is used to provide counter-ions and an additional cation.
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) | 1990-10-12 | 1991-04-13 | 1991-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-12 | 1995-04-13 | 1995-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-12 | 1999-04-13 | 1999-10-13 | $7700.00 | Window Closed / Lapsed |