US5021192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colloidal dispersions of cerium (IV) compound
Assignee: Rhodia Chimie SAS
•
Filing: 1987-03-26
•
Granted: 1991-06-04
•
Expires: 2007-03-26
Abstract
Abstract Highly concentrated, aqueous colloidal dispersions of a cerium (IV) compound, adapted for the impregnation of catalyst supports, are prepared by reacting an aqueous solution of a cerium (IV) salt with a base, to precipitate a certain cerium hydroxynitrate, separating and washing said precipitate, and then dispersing the washed precipitate in an aqueous acid medium.
Inventors
- 👤 Claire David
- 👤 Claude Magnier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:56
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/20; C01F17/206; B; B82; B82Y; B82Y30/00; B01; B01J; B01J23/00; B01J23/10; B01J27/00; B01J27/24; B01J27/25; C01F17/224; C01F17/235; C01F17/276; C01P; C01P2004/00; C01P2004/60; C01P2004/64
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
39 words
An aqueous acid colloidal dispersion of cerium (IV) hydroxynitrate comprising from about 400 g/l to about 700 g/l of cerium values, expressed as CeO 2 , wherein said aqueous acid colloidal dispersion comprises a pH between 0.5 and 2.
Claim 2
Dependent Claim
39 words
An aqueous acid colloidal dispersion of cerium (IV) hydroxynitrate comprising from about 400 g/l to about 700 g/l of cerium values, expressed as CeO 2 , wherein said aqueous acid colloidal dispersion comprises a pH between 0.5 and 2.
Claim 3
Dependent Claim
29 words
The aqueous acid colloidal dispersion as defined by claim 1, comprising essentially pure cerium (VI) hydroxynitrate, the amount of cerium (IV) in colloidal form ranging from 70 to 100%.
Claim 4
Dependent Claim
22 words
The aqueous acid colloidal dispersion as defined by claim 1, having a density of from 1.0 to 1.6, measured at 20° C.
Claim 5
Dependent Claim
23 words
The aqueous acid colloidal dispersion as defined by claim 1, said colloids having a mean hydrodynamic diameter of from 80 to 400 Å.
Claim 6
Dependent Claim
23 words
The aqueous acid colloidal dispersion as defined by claim 4, said colloids having a mean hydrodynamic diameter of from 80 to 300 Å.
Claim 7
Dependent Claim
39 words
The aqueous acid colloidal dispersion as defined by claim 1, said cerium (IV) hydroxynitrate having the Formula (I): Ce(OH).sub.x (NO.sub.3).sub.y.nH.sub.2 O (I) wherein y ranges from 0.25 to 0.35; x =4-y; and n ranges from 0 to about 20.
Claim 8
Dependent Claim
26 words
The aqueous acid colloidal dispersion as defined by claim 6, wherein n ranges from 2 to 5 in said cerium (IV) hydroxynitrate having the formula (I).
Claim 9
Dependent Claim
95 words
A process for the preparation of the aqueous acid colloidal dispersion as defined by claim 1, comprising precipitating a cerium (IV) hydroxynitrate having the Formula (I): Ce(OH).sub.x (NO.sub.3).sub.y ·nH.sub.2 O (I) wherein y ranges from 0.25 to 0.35; x =4-y; and n ranges from 0 to about 20 by reacting an aqueous solution of a cerium (IV) salt with a quantity of base sufficient to maintain said solution at a pH between 4.0 and 9.0, washing said precipitate, and dispersing the washed precipitate in an aqueous acid medium having a pH between 0.5 and 2.
Claim 10
Dependent Claim
15 words
The process as defined by claim 8, said cerium (IV) salt comprising cerium (IV) hydroxynitrate.
Claim 11
Dependent Claim
23 words
The process as defined by claim 9, said cerium (IV) hydroxynitrate having been prepared by electrolytic oxidation of a solution of ceriuos nitrate.
Claim 12
Dependent Claim
22 words
The process as defined by claim 9, said cerium (IV) hydroxynitrate having been prepared by reacting nitric acid with hydrated ceric oxide.
Claim 13
Dependent Claim
29 words
The process as defined by claim 8, further comprising pre-neutralizing said aqueous solution of the cerium (IV) salt such that the proportion of neutralization ranges from -4 to 2.
Claim 14
Dependent Claim
26 words
The process as defined by claim 8, wherein the concentration of said solution of the cerium (IV) salt ranges from 0.3 to 3 moles per liter.
Claim 15
Dependent Claim
13 words
The process as defined by claim 8, said base comprising an ammonia solution.
Claim 16
Dependent Claim
19 words
The process as defined by claim 8, wherein the pH of the reaction medium ranges from 5 to 7.
Claim 17
Dependent Claim
27 words
The process as defined by claim 8, wherein said dispersing in an aqueous acid medium comprises heating at a temperature of between 50° C. and 70° C.
Claim 18
Dependent Claim
77 words
A process for the preparation of the aqueous acid colloidal dispersion as defined by claim 1, comprising precipitating said cerium (IV) hydroxynitrate by reacting an aqueous solution of a cerium (IV) salt with a quantity of base sufficient to maintain said solution at a pH between 4.0 and 9.0, separating said precipitate from the solution, washing said separated precipitate, and directly dispersing the washed precipitate in an aqueous acid medium having a pH between 0.5 and 2.
Claim 19
Dependent Claim
56 words
A process for the preparation of cerium (IV) hydroxynitrate comprising precipitating said cerium (IV) hydroxynitrate having a mole ratio of NO 3 /CeO 2 of from 0.25 to 0.35 by reacting an aqueous solution of a cerium (IV) salt with a quantity of base sufficient to maintain said solution at a pH between 4.0 and 9.0.
Claim 20
Dependent Claim
56 words
A process for the preparation of cerium (IV) hydroxynitrate comprising precipitating said cerium (IV) hydroxynitrate having a mole ratio of NO 3 /CeO 2 of from 0.25 to 0.35 by reacting an aqueous solution of a cerium (IV) salt with a quantity of base sufficient to maintain said solution at a pH between 4.0 and 9.0.
Claim 21
Dependent Claim
40 words
The process as defined by claim 18, further comprising washing said cerium (IV) hydroxynitrate and dispersing said washed cerium (IV) hydroxynitrate in an aqueous acid medium having a pH between 0.5 and 2.0 to form an aqueous acid colloidal dispersion.
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) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |