US3691089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of colloidal silicic acid coated with mixture of metallic oxides, and product
Assignee: Evonik Operations GmbH
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Filing: 1970-08-05
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Granted: 1972-09-12
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Expires: 1990-08-05
Abstract
Abstract Silicic acid sols are treated with a mixture of trivalent metal salts and bivalent metal salts which react to form metallic oxide coatings on the surface of the sol particles. The sols as a result are rendered more stable, as indicated by the fact that the viscosity of said sols remains constant and the tendency to gel is eliminated. The sols can be dried to give a finely divided product.
Inventors
- 👤 Karl-Heinz Janzon
- 👤 Eugen Meyer Simon
- 👤 Heinrich Schwab
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:36
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/24; B; B01; B01J; B01J21/00; B01J21/20; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/146; C01B33/149; C04B12/00; C04B12/04; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/309; C09C3/00; C09C3/06; C09C3/063; C09C3/08; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; C04B2111/00; C04B2111/00474; C04B2111/00482; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/584
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
51 words
The process of claim 1 wherein the silicic acid content of said sol used as starting material is in the range from 15 to 40 percent and the pH of said sol is in the range from 3.5 to 6.5 and said sol has a specific surface area of 50-500 m2/g.
Claim 2
Dependent Claim
30 words
The process of claim 2 wherein the pH of said sol is in the range from 3.8 to 4.8 and said sol has a specific surface area of 60-250 m2/g.
Claim 3
Dependent Claim
96 words
The process of claim 1 wherein the trivalent metal is in the form of a basic complex of the formula (Me2(OH)5A)x. nH2O where x is an integer from 1 to 5, n is equal to or greater than zero, Me is said trivalent metal, A is an anion selected from the group consisting of Cl , 1/2 SO4 , and NO3 , and wherein said complex is combined with at least one divalent metal salt of a metal selected from said group consisting of Mg, Ca, Sr, Ba, Fe, Co, Ni, Mn, Cu, Zn and Cd.
Claim 4
Dependent Claim
64 words
The process of claim 1, wherein the divalent and trivalent metal salts are in the form of a mixed basic complex having the formula (MeaIIMebIII(OH)mAn) . w where the ratio a/b is between 0.03 and 0.5, the ratio b/n is between 0.25 and 1, and m equals 2a+ 3b- n and w signifies the number of water molecules associated with said complex basic salt.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the divalent metal salt is an acetate.
Claim 6
Dependent Claim
25 words
The process of claim 1 wherein the amounts of salts are selected to provide a mol ratio of MeO to Me2O3 from 0.05 to 0.75.
Claim 7
Dependent Claim
31 words
The process of claim 1 wherein the amounts of starting sol and salts are chosen to provide for a coated silicic acid sol which has a silica content of 5-25 percent.
Claim 8
Dependent Claim
51 words
The process of claim 1 including the step of rendering the silicic acid sol used as starting compound salt-free by passing it through an ion exchange system consisting of an acid and a basic ion exchange compound to adjust the pH of the sol to a value between 3.8 and 4.8.
Claim 9
Dependent Claim
117 words
A metal-oxide coated silicic acid sol of high stability consisting of spherical silicic acid particles with a diameter of 3-60 m Mu coated with divalent and trivalent metal oxides, the SiO2 content of the sol being between 5 and 25 percent, the metal of said trivalent metal oxide being a member selected from the group consisting of Al, Fe and Cr, the metal of said divalent metal oxide being a member selected from the group consisting of Mg, Ca, Sr, Ba, Fe, Co, Ni, Mn, Cu, Zn and Cd and said metal oxides being present at mole ratios of Me2O3 to SiO2 between about 0.02 and 0.5 and of MeO to Me2O3 between about 0.05 and 1.
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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |