US4714567A
Expired / Lapsed
US
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Reacting alumina hydrate sol and an organic material to form a stable monolithic gel
Assignee: Alcoa Corp
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Filing: 1985-10-31
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Granted: 1987-12-22
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Expires: 2005-10-31
Abstract
Abstract A stable monolithic gel produced by reacting an alumina hydrate sol with an organic reactant selected from the group consisting of polycarboxylic acids having esterified acid groups, anhydrides of polycarboxylic acids, and water-soluble cationic or neutral polyacrylamides. A particularly preferred gel is made by reacting an alumina monohydrate sol with dimethyl oxalate. The preferred monolithic gel remains transparent or slightly cloudy upon storage with little syneresis.
Inventors
- 👤 Max E. Roha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:04
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/0052; B01J13/0065
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
84 words
A method for preparing a stable monolithic gel comprising alumina hydrate combined with an organic material, said method comprising (a) preparing a sol comprising a colloidal dispersion of alumina hydrate in an aqueous solution, (b) mixing said sol and an organic reactant selected from the group consisting of polycarboxylic acids having esterified acid groups and anhydrides of polycarboxylic acids, and (c) reacting said alumina hydrate with said organic reactant, thereby to form a monolithic gel comprising alumina hydrate chemically combined with an organic material.
Claim 2
Independent Claim
84 words
A method for preparing a stable monolithic gel comprising alumina hydrate combined with an organic material, said method comprising (a) preparing a sol comprising a colloidal dispersion of alumina hydrate in an aqueous solution, (b) mixing said sol and an organic reactant selected from the group consisting of polycarboxylic acids having esterified acid groups and anhydrides of polycarboxylic acids, and (c) reacting said alumina hydrate with said organic reactant, thereby to form a monolithic gel comprising alumina hydrate chemically combined with an organic material.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1 wherein said sol comprises a colloidal dispersion of alumina monohydrate.
Claim 4
Dependent Claim
27 words
A method as claimed in claim 2 wherein step (c) comprises heating said alumina monohydrate and said organic reactant to an elevated temperature of about 50°-100° C.
Claim 5
Dependent Claim
36 words
A method as claimed in claim 1 wherein step (a) includes hydrolyzing an aluminum alkoxide in an aqueous acidic solution to form a sol comprising a colloidal dispersion of alumina monohydrate in an aqueous acidic solution.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 1 wherein said organic reactant comprises a water-soluble diester of an aliphatic dicarboxylic acid containing about 2-6 carbon atoms.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1 wherein said organic reactant comprises a water-soluble diester of oxalic acid, malonic acid, tartaric acid or succinic acid.
Claim 8
Dependent Claim
14 words
A method as claimed in claim 1 wherein said organic reactant comprises dimethyl oxalate.
Claim 9
Dependent Claim
23 words
A method as claimed in claim 7 wherein the dimethyl oxalate is dissolved in methanol or ethanol or water prior to step (b).
Claim 10
Dependent Claim
19 words
A method as claimed in claim 1 wherein said organic reactant is a water-soluble anhydride of a polycarboxylic acid.
Claim 11
Dependent Claim
14 words
A method as claimed in claim 1 wherein said organic reactant is maleic anhydride.
Claim 12
Dependent Claim
24 words
A method as claimed in claim 1 wherein step (C) is performed in an aqueous solution having a pH of less than about 7.
Claim 13
Dependent Claim
15 words
A generally transparent or slightly opalescent monolithic gel produced by the method of claim 1.
Claim 14
Dependent Claim
60 words
The gel of claim 12 produced by (a) preparing a sol comprising a colloidal dispersion of alumina monohydrate in an aqueous acidic solution, (b) mixing said sol and an organic reactant comprising a water-soluble diester of oxalic acid, and (c) reacting said alumina monohydrate and said organic reactant at an elevated temperature of about 50°-100° C. in an aqueous solution.
Claim 15
Independent Claim
86 words
A method for preparing a stable monolithic gel comprising alumina hydrate combined with an organic material, said method comprising (a) preparing a sol comprising a colloidal dispersion of alumina hydrate in an aqueous solution, (b) mixing said sol and an organic reactant comprising a water-soluble cationic or neutral polyacrylamide, and (c) reacting said alumina hydrate with said organic reactant in an aqueous solution having a pH of less than about 7, thereby to form a monolithic gel comprising alumina hydrate chemically combined with an organic material.
Claim 16
Independent Claim
86 words
A method for preparing a stable monolithic gel comprising alumina hydrate combined with an organic material, said method comprising (a) preparing a sol comprising a colloidal dispersion of alumina hydrate in an aqueous solution, (b) mixing said sol and an organic reactant comprising a water-soluble cationic or neutral polyacrylamide, and (c) reacting said alumina hydrate with said organic reactant in an aqueous solution having a pH of less than about 7, thereby to form a monolithic gel comprising alumina hydrate chemically combined with an organic material.
Claim 17
Dependent Claim
15 words
A method as claimed in claim 14 wherein said organic reactant is a cationic polyacrylamide.
Claim 18
Dependent Claim
27 words
A method as claimed in claim 14 wherein step (c) comprises heating said alumina hydrate and said organic reactant to an elevated temperature of about 50°-100° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-12-21 | 1991-06-22 | 1991-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-21 | 1995-06-22 | 1995-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-21 | 1999-06-22 | 1999-12-22 | $7700.00 | Window Closed / Lapsed |