US3853755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Osmosis efficiency from tannin treatment of non-porous semipermeable membranes having hydrous heavy metal coatings
Assignee: EIDP Inc
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Filing: 1972-11-06
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Granted: 1974-12-10
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Expires: 1992-11-06
Abstract
Abstract The passage of salts through a non-porous semipermeable membrane with a coating layer of a hydrous heavy metal composition under reverse osmosis conditions is reduced after the membrane and the coating layer have been contacted with a solution of a hydrolyzable tannin.
Inventors
- 👤 J Ganci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:04
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
A PROCESS FOR SEPARATING SOLVENT FROM AN AQUEOUS SOLUTION OF INORGANIC SALTS, COMPRISING CONTACTING A PERMSELECTIVE STRUCTURE WITH SAID SOLUTION UNDER A PRESSURE GREATER THAN THE OSMOTIC PRESSURE OF THE SOLUTION, SAID PERMSELECTIVE STRUCTURE COMPRISING A NON-POROUS SEMIPERMEABLE MEMBRANE SELECTED FROM CELLULOSIC DERIVATIVE MEMBRANES AND NITROGEN-LINKED AROMATIC POLYMER MEMBRANES AND A COATING OF HYDROUS HEAVY METAL COMPOSITIONS AND SAID STRUCTURE HAVING BEEN TREATED WITH A SOLUTION OF A HYDROLYZABLE TANNIN IN AN AMOUNT AND UNDER CONDITIONS WHICH RESULT IN A SIGNIFICANT REDUCTION IN SALT PASSAGE THROUGH THE STRUCTURE UNDER REVERSE OSMOSIS CONDITIONS.
Claim 2
Dependent Claim
92 words
A PROCESS FOR SEPARATING SOLVENT FROM AN AQUEOUS SOLUTION OF INORGANIC SALTS, COMPRISING CONTACTING A PERMSELECTIVE STRUCTURE WITH SAID SOLUTION UNDER A PRESSURE GREATER THAN THE OSMOTIC PRESSURE OF THE SOLUTION, SAID PERMSELECTIVE STRUCTURE COMPRISING A NON-POROUS SEMIPERMEABLE MEMBRANE SELECTED FROM CELLULOSIC DERIVATIVE MEMBRANES AND NITROGEN-LINKED AROMATIC POLYMER MEMBRANES AND A COATING OF HYDROUS HEAVY METAL COMPOSITIONS AND SAID STRUCTURE HAVING BEEN TREATED WITH A SOLUTION OF A HYDROLYZABLE TANNIN IN AN AMOUNT AND UNDER CONDITIONS WHICH RESULT IN A SIGNIFICANT REDUCTION IN SALT PASSAGE THROUGH THE STRUCTURE UNDER REVERSE OSMOSIS CONDITIONS.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein the non-porous semipermeable membrane is a nitrogen linked aromatic polymer of the general formula - L - R -wherein each L is independently a linking group and is a
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein the non-porous semipermeable membrane is a cellulosic derivative of the general formula
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein the tannin is tannic acid.
Claim 6
Dependent Claim
19 words
The process of claim 4 wherein the tannic acid solution has a pH of about 5 to about 7.
Claim 7
Dependent Claim
24 words
The process of claim 1 wherein the permselective structure contains at least about 5 micrograms of hydrolyzable tannin per square centimeter of coating layer.
Claim 8
Dependent Claim
24 words
The process of claim 1 wherein the permselective structure contains at least about 10 micrograms of hydrolyzable tannin per square centimeter of coating layer.
Claim 9
Dependent Claim
24 words
The process of claim 1 wherein the permselective structure contains at least about 20 micrograms of hydrolyzable tannin per square centimeter of coating layer.
Claim 10
Dependent Claim
14 words
The process of claim 1 wherein reduction in salt passage is at least 50%.
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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |