US4752458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Structured silicas
Assignee: Individual
•
Filing: 1986-06-05
•
Granted: 1988-06-21
•
Expires: 2006-06-05
Abstract
Abstract A method of preparing spherical microparticles of silica comprising adding an acid solution to a silicate solution before or after addition of an alkali metal alginate, ammonium alginate, starch, gelatin, pectin or mixtures thereof. The microparticles can be used to prepare macroporous materials having a controlled pore structure.
Inventors
- 👤 Eric Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:03
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/14; B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/103; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/152; C01B33/154
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
57 words
A method of preparing microparticles of silica consisting of the step adding an acid solution ot a solution of soluble silicate and prior to the formation of a silica gel adding an organic polymer solution, the polymer being selected from the group consisting of an alkali metal alginate, ammonium alginate, starch, gelatin, pectin, or a mixture thereof.
Claim 2
Independent Claim
57 words
A method of preparing microparticles of silica consisting of the step adding an acid solution ot a solution of soluble silicate and prior to the formation of a silica gel adding an organic polymer solution, the polymer being selected from the group consisting of an alkali metal alginate, ammonium alginate, starch, gelatin, pectin, or a mixture thereof.
Claim 3
Dependent Claim
32 words
A method as claimed in claim 1, wherein the acid solution is added to the soluble silicate before addition of the alkali metal alginate, ammonium alginate, starch, gelatin, pectin or mixtures thereof.
Claim 4
Dependent Claim
32 words
A method as claimed in claim 1, wherein the acid solution is added to the soluble silicate after addition of the alkali metal alginate, ammonium alginate, starch, gelatin, pectin or mixtures thereof.
Claim 5
Dependent Claim
13 words
A method as claimed in claim 1, wherein the microparticles are substantially spherical.
Claim 6
Dependent Claim
18 words
A method as claimed in claim 4, wherein the microparticles have diameters of between 0.5 and 250 microns.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 1 wherein the silicate solution contains from 3 to 25% w/v silica.
Claim 8
Dependent Claim
20 words
A method as claimed in claim 1 wherein the acid solution contains from 1 to 10% by volume of acid.
Claim 9
Dependent Claim
18 words
A method as claimed in claim 1 wherein the pH of the reaction mixture is maintained above 7.
Claim 10
Dependent Claim
22 words
A method as claimed in claim 1, wherein the solutions are maintained at a temperature of between 0° C. and 100° C.
Claim 11
Dependent Claim
12 words
Microparticles of silica prepared by the method as claimed in claim 1.
References Cited (Backward Citations)
US4621936A
Cited
US4564556A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-21 | 1991-12-21 | 1992-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-21 | 1995-12-21 | 1996-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-21 | 1999-12-21 | 2000-06-21 | $7700.00 | Window Closed / Lapsed |