Patent US4520044A successfully refreshed from Google Patents.
US4520044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of composite membranes
Assignee: EIDP Inc
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Filing: 1984-07-30
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Granted: 1985-05-28
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Expires: 2004-07-30
Abstract
Abstract A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.
Inventors
- 👤 Sherman A. Sundet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:35
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D71/00; B01D71/06; B01D71/56
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
104 words
A process for forming a thin film composite membrane comprising forming a membrane from a solution of a polysulfone in a polar, organic solvent containing from 10 to 20% by weight polysulfone, quenching the resulting membrane in an aqueous bath containing 0.1 to 10% weight/volume m-phenylenediamine, removing the resulting porous polysulfone film containing m-phenylenediamine from the aqueous bath, and immersing said porous polysulfone film in a water immiscible solution comprising 0.05 to 5% weight/volume trimesoyl chloride, cyclohexane-1,3,5-tricarbonyl chloride, or mixtures thereof whereby the m-phenylene diamine reacts with the trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride to form a continuous layer supported by the porous polysulfone membrane.
Claim 2
Dependent Claim
104 words
A process for forming a thin film composite membrane comprising forming a membrane from a solution of a polysulfone in a polar, organic solvent containing from 10 to 20% by weight polysulfone, quenching the resulting membrane in an aqueous bath containing 0.1 to 10% weight/volume m-phenylenediamine, removing the resulting porous polysulfone film containing m-phenylenediamine from the aqueous bath, and immersing said porous polysulfone film in a water immiscible solution comprising 0.05 to 5% weight/volume trimesoyl chloride, cyclohexane-1,3,5-tricarbonyl chloride, or mixtures thereof whereby the m-phenylene diamine reacts with the trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride to form a continuous layer supported by the porous polysulfone membrane.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein concentration of m-phenylene diamine in this aqueous quench bath is from 0.5 to 5% by weight/volume.
Claim 4
Dependent Claim
16 words
The process of claim 2 wherein the polar organic solvent for the polysulfone is dimethyl formamide.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein the solvent for the trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride is a chlorofluorocarbon.
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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |