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US3755158A
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US
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Process for capturing metal ions
Assignee: Ajinomoto Co Inc
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Filing: 1971-08-04
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Granted: 1973-08-28
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Expires: 1991-08-04
Abstract
Abstract Cations of metals other than the alkali metals may be precipitated practically completely from their aqueous solutions at a pH of 4 or higher by N-acylamino acids whose acyl group is alkanoyl or alkenoyl having seven to 25 carbon atoms, the acylamino group being connected with the carboxyl group by divalent alkylene having one to five carbon atoms. The voluminous precipitates include even more of the metal ions originally present and settle faster in the presence of small amounts of polyhydric alcohols, polyethers, alkali metal silicates, or alkali metal borates. Water polluted with heavy metals can be made potable by this method.
Inventors
- 👤 S Inazuka
- 👤 M Takehara
- 👤 R Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:36
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C02F1/5236; C02F1/5272
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
20 words
A method as set forth in claim 1, wherein said amount is 0.01 to 10 stoichiometric equivalents of said cations.
Claim 2
Dependent Claim
17 words
the acyl radical of said N-acylamino acid being alkanoyl or alkenoyl having 7 to 25 carbon atom,
Claim 3
Dependent Claim
35 words
the acylamino group of said N-acylamino acid being connected with a carboxyl group of said N-acylamino acid by divalent alkylene having one to five carbon atoms; and b. separating the precipitated cations from said medium.
Claim 4
Dependent Claim
20 words
A method as set forth in claim 1, wherein said amount is 1.0 to 4.0 stoichiometric equivalents of said cations.
Claim 5
Dependent Claim
19 words
A method as set forth in claim 3, wherein said alkanoyl or alkenoyl has 11 to 21 carbon atoms.
Claim 6
Dependent Claim
85 words
A method as set forth in claim 1, wherein an amount of at least one capturing assistant effective for enhancing the settling velocity of the precipitated cations in said medium and for reducing the concentration of residual cations in said medium after said precipitating is dispersed in said medium, said capturing assistant being an organic compound having two or more alcoholic hydroxyl groups, an organic compound having a polyoxyethylene radical including more than two ether linkages, an alkali metal silicate, or an alkali metal borate.
Claim 7
Dependent Claim
29 words
A method as set forth in claim 5, wherein the amount of said capturing assistant is between 10 7 and 10 percent of the weight of said N-acylamino acid.
Claim 8
Dependent Claim
26 words
A method as set forth in claim 6, wherein the amount of said capturing assistant is between 10 5 and 10 1 percent of said weight.
Claim 9
Dependent Claim
16 words
A method as set forth in claim 6, wherein said capturing assistant is a polyhydric alcohol.
Claim 10
Dependent Claim
15 words
A method as set forth in claim 6, wherein said capturing assistant is a saccharide.
Claim 11
Dependent Claim
16 words
A method as set forth in claim 6, wherein said capturing assistant is a polyalkylene glycol.
Claim 12
Dependent Claim
21 words
A method as set forth in claim 6, wherein said capturing assistant is an alkali metal silicate or alkali metal borate.
Claim 13
Dependent Claim
21 words
A method as set forth in claim 1, wherein the pH of said medium is lower than 8 after said dissolving.
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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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |