Patent US3872001A successfully refreshed from Google Patents.
US3872001A
Expired / Lapsed
US
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Removal of heavy metal pollutants from aqueous media
Assignee: Celanese Corp
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Filing: 1973-05-31
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Granted: 1975-03-18
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Expires: 1993-05-31
Abstract
Abstract A porous film is disclosed which is capable of removing heavy metal pollutants from aqueous media. The film is basically prepared from an acid-containing polymer which has been rendered porous or micro-porous by standard methods. Reacted with the acid groups in the polymeric film backbone is a chelate-divalent metal complex which chelate is capable of forming a complex with the heavy metal pollutants to be removed from the aqueous media.
Inventors
- 👤 Howard J Davis
- 👤 Leonard A Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:27
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D61/00; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/18; B01D71/76; B01D71/82; C; C02; C02F; C02F1/00; C02F1/28; C02F1/285; C02F9/00; C02F2101/00; C02F2101/10; C02F2101/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
87 words
A PROCESS FOR REMOVING POLLUTANT HEAVY METAL CATIONS FROM AM AQUEOUS MEDIA CONTAINING SAME WHICH COMPRISES PASSING SAID POLLUTANT-CONTAINING AQUEOUS MEDIA THROUGH A SUBSTANTIALLY WATER INSENSITIVE, FLEXIBLE BASE, POROUS POLYMERIC FILM THEREBY FORMING A COMPLEX WITH THE POLLUTANT METAL CATIONS TO BE REMOVED FROM THE AQUEOUS MEDIA, SAID FILM BEING PREPARED FROM A POLYMER CONTAINING FROM ABOUT 0.01 TO 3.0 FREE HYDROXYL GROUPS PER GRAM OF POLYMER WHICH HAS BEEN REACTED WITH A POLYFUNCTIONAL CARBOXYLIC OR SULFONIC ACID OR ANHYDRIDE TO PRODUCE AN ACID-CONTAINING POLYMER AND SUBSE
Claim 2
Dependent Claim
87 words
A PROCESS FOR REMOVING POLLUTANT HEAVY METAL CATIONS FROM AM AQUEOUS MEDIA CONTAINING SAME WHICH COMPRISES PASSING SAID POLLUTANT-CONTAINING AQUEOUS MEDIA THROUGH A SUBSTANTIALLY WATER INSENSITIVE, FLEXIBLE BASE, POROUS POLYMERIC FILM THEREBY FORMING A COMPLEX WITH THE POLLUTANT METAL CATIONS TO BE REMOVED FROM THE AQUEOUS MEDIA, SAID FILM BEING PREPARED FROM A POLYMER CONTAINING FROM ABOUT 0.01 TO 3.0 FREE HYDROXYL GROUPS PER GRAM OF POLYMER WHICH HAS BEEN REACTED WITH A POLYFUNCTIONAL CARBOXYLIC OR SULFONIC ACID OR ANHYDRIDE TO PRODUCE AN ACID-CONTAINING POLYMER AND SUBSE
Claim 3
Dependent Claim
37 words
The process of claim 1 wherein the log of the stability constant of the divalent metal chelate is at least 3 points higher than the log of the stability constant of its corresponding sodium or potassium chelate.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the polymeric film is cellulose acetate.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the polyfunctional anhydride is phthalic anhydride.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein the divalent metal chelate is ethylenediaminetetracetic acid.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |