US4053568A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of antacid aluminum hydroxycarbonate hydrate
Assignee: Madaus Holding GmbH
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Filing: 1975-03-28
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Granted: 1977-10-11
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Expires: 1995-03-28
Abstract
Abstract A basic aluminum hydroxycarbonate hydrate, usable as an antacid, is prepared by simultaneously adding aqueous solutions of aluminum sulfate and alkali hydrogen carbonate or alkali carbonate to water while maintaining a neutral or weakly alkaline pH and adjusting the pH-value of the reaction mixture, after completed precipitation, to about 6.0 by adding an aluminum salt of a strong acid.
Inventors
- 👤 Rolf Hermann Heinrich Madaus
- 👤 Klaus Gorler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:31
CPC Classifications
B; B21; B21D; B21D39/00; B21D39/06; B21D39/066; C; C01; C01F; C01F7/00; C01F7/77
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
70 words
Process for the preparation of basic aluminum hydroxycarbonate hydrate which comprises simultaneously adding aqueous solutions of aluminum sulfate and alkali metal hydrogen carbonate or carbonate to water while maintaining an initial pH-value of from 6.8 to 7.8, permitting the resulting precipitation to run to completion, and then in a subsequent step, adding an aluminum salt of a strong acid to adjust the pH-value of the reaction mixture to about 6.0.
Claim 2
Dependent Claim
70 words
Process for the preparation of basic aluminum hydroxycarbonate hydrate which comprises simultaneously adding aqueous solutions of aluminum sulfate and alkali metal hydrogen carbonate or carbonate to water while maintaining an initial pH-value of from 6.8 to 7.8, permitting the resulting precipitation to run to completion, and then in a subsequent step, adding an aluminum salt of a strong acid to adjust the pH-value of the reaction mixture to about 6.0.
Claim 3
Dependent Claim
25 words
Process as claimed in claim 1 wherein the addition of said aqueous solutions to water and the resulting precipitation is carried out at room temperature.
Claim 4
Dependent Claim
26 words
Process as claimed in claim 1 wherein the addition of said aqueous solutions to water and the resulting precipitation is carried out at below room temperature.
Claim 5
Dependent Claim
14 words
Process as claimed in claim 3 wherein the temperature is 16 to 18° C.
Claim 6
Dependent Claim
21 words
Process as claimed in claim 1 wherein the mole ratio of aluminum sulfate to alkali hydrogen carbonate is 1:2 to 1:3.5.
Claim 7
Dependent Claim
12 words
Process as claimed in claim 5 wherein said mole ratio is 1:2.5.
Claim 8
Dependent Claim
30 words
Process as claimed in claim 1 wherein said reaction mixture to which the aluminum salt has been added is maintained for a holding period of at least about 12 hours.
Claim 9
Dependent Claim
14 words
Process as claimed in claim 7 wherein said holding period is about 15 hours.
Claim 10
Dependent Claim
32 words
Process as claimed in claim 1 wherein said reaction mixture with the aluminum salt added thereto is filtered and the precipitate freed of water by contacting it with a water soluble alcohol.
Claim 11
Dependent Claim
13 words
Process as claimed in claim 9 wherein said water-miscible organic liquid is ethanol.
Claim 12
Dependent Claim
24 words
Process as claimed in claim 10 wherein said water-free precipitate is dried in a vacuum at a temperature of about 40° to 50° C.
Claim 13
Dependent Claim
21 words
Process as claimed in claim 1 wherein the alkali metal hydrogen carbonate or carbonate solution is a sodium hydrogen carbonate solution.
Claim 14
Dependent Claim
18 words
Process as claimed in claim 1 wherein the alkali metal hydrogen carbonate solution is a sodium carbonate solution.
Claim 15
Dependent Claim
17 words
Process as claimed in claim 1 wherein said aluminum salt of a strong acid is aluminum chloride.
Claim 16
Dependent Claim
17 words
Process as claimed in claim 1 wherein said aluminum salt of a strong acid is aluminum nitrate.
Claim 17
Dependent Claim
17 words
Process as claimed in claim 1 wherein said aluminum salt of a strong acid is aluminum sulfate.
Claim 18
Dependent Claim
15 words
Process as claimed in claim 1 wherein said initial pH-value is from 7.0 to 7.3.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |