US4247401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reverse osmosis separation process using porous asymmetric acetyl cellulose membrane
Assignee: Aligena AG
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Filing: 1978-08-31
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Granted: 1981-01-27
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Expires: 1998-08-31
Abstract
Abstract A method for the separation of organic or metallo-organic substances from salts by reverse osmosis is provided. The membranes used are asymmetric acetyl cellulose membranes modified by covalently bonded residues of reactive dyestuffs containing ionizable groups. The diameter of the pores on the surface of the membrane is 5 to 100 A.
Inventors
- 👤 Rene Bloch
- 👤 Jacov Yonath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:40
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/02; B01D61/025; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
A method for the separation of organic or metallo-organic ionogenic substances from salts by reverse osmosis which comprises applying pressure on an aqueous composition containing the said organic or metallo-organic ionogenic substances and salts dissolved therein, the said aqueous composition being in contact with a porous asymmetric membrane substantially consisting of acetyl cellulose material modified by covalently bonded residues of reactive dyestuffs containing ionizable groups, said membrane having been subjected to a heat treatment at a temperature of from 60° to 90° C. for from 1 to 30 minutes and having on its surface uniform pores with a diameter of 5-50 A.
Claim 2
Independent Claim
102 words
A method for the separation of organic or metallo-organic ionogenic substances from salts by reverse osmosis which comprises applying pressure on an aqueous composition containing the said organic or metallo-organic ionogenic substances and salts dissolved therein, the said aqueous composition being in contact with a porous asymmetric membrane substantially consisting of acetyl cellulose material modified by covalently bonded residues of reactive dyestuffs containing ionizable groups, said membrane having been subjected to a heat treatment at a temperature of from 60° to 90° C. for from 1 to 30 minutes and having on its surface uniform pores with a diameter of 5-50 A.
Claim 3
Dependent Claim
38 words
A method according to claim 1, wherein the said membrane contains the residues of an azo dyestuff that contains sulfonic acid groups which are connected to the remaining part of the acetyl cellulose molecule through a triazine residue.
Claim 4
Dependent Claim
26 words
A method according to claim 1, wherein the said membrane contains carboxylic acid groups, sulfonic acid groups, amino groups or quaternary ammonium groups as ionizable groups.
Claim 5
Independent Claim
96 words
A method for the purification of the effluents occurring in the production and application of dyestuffs by reverse osmosis which comprises applying pressure on an aqueous composition containing said effluents, the said aqueous composition being in contact with a porous asymmetric membrane substantially consisting of acetyl cellulose material modified by covalently bonded residues of reactive dyestuffs containing ionizable groups, said membrane having been subjected to a heat treatment at a temperature of from 60° to 90° C. for from 1 to 30 minutes and having on its surface uniform pores with a diameter of 5-50 A.
Claim 6
Independent Claim
96 words
A method for the purification of the effluents occurring in the production and application of dyestuffs by reverse osmosis which comprises applying pressure on an aqueous composition containing said effluents, the said aqueous composition being in contact with a porous asymmetric membrane substantially consisting of acetyl cellulose material modified by covalently bonded residues of reactive dyestuffs containing ionizable groups, said membrane having been subjected to a heat treatment at a temperature of from 60° to 90° C. for from 1 to 30 minutes and having on its surface uniform pores with a diameter of 5-50 A.
Claim 7
Dependent Claim
38 words
A method according to claim 4, wherein the said membrane contains the residues of an azo dyestuff that contains sulfonic acid groups which are connected to the remaining part of the acetyl cellulose molecule through a triazine residue.
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) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |