Patent US4861628A successfully refreshed from Google Patents.
US4861628A
Expired / Lapsed
US
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Thin film composite membrane prepared by suspension deposition
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1987-10-14
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Granted: 1989-08-29
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Expires: 2007-10-14
Abstract
Abstract Thin film membranes of polyurea, polyureapolyurethane alloy, polyurea-polyurea/urethane alloy or polyurea/urethane are prepared by deposition of a thin film of suspension of the selected polymer on a thick permeable support layer by the technique of preparing a suspension of the selected polymer in a solvent which does not dissolve the thick permeable support layer and permitting the solvent to evaporate and/or permeate through the thick-permeable layer.
Inventors
- 👤 Robert C. Schucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:26
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/24; B01D61/246; B01D61/36; B01D61/362; B01D63/00; B01D63/02; B01D67/00; B01D67/0039; B01D67/0048; B01D69/00; B01D69/08; B01D69/10; B01D69/107; B01D69/12; B01D69/1213; B01D69/125; B01D71/00; B01D71/06; B01D71/54; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C08G18/28; C08G18/30; C08G18/32; C08G18/3225; C08G18/3237; C08G18/3243; C10; C10G; C10G31/00; C10G31/11; B01D2323/00; B01D2323/12; Y; Y10; Y10S; Y10S264/00; Y10S264/18
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
133 words
A method for producing thin film composite membranes for separating aromatic hydrocarbons from non-aromatic hydrocarbons, consisting of a thin active layer of polymer, selected from polyurea/urethane copolymer, polyurea, polyurea-polyurethane alloy, or a polyurea-polyurea/urethane alloy on a porous support layer by synthesizing the polymer in a dispersing solvent thereby producing a dispersion-suspension of the polymer in the dispersing solvent which does not dissolve the porous support layer, the polymer being present in the dispersion-suspension at a concentration of from about 0.5 to about 10% polymer, depositing a layer of the dispersion-suspension on one face of the porous support layer, and permitting the dispersing solvent to either evaporate from the dispersion-suspension layer or permeate through the porous support layer, thereby depositing the thin film of a thickness 2 microns or less on the support layer.
Claim 2
Independent Claim
133 words
A method for producing thin film composite membranes for separating aromatic hydrocarbons from non-aromatic hydrocarbons, consisting of a thin active layer of polymer, selected from polyurea/urethane copolymer, polyurea, polyurea-polyurethane alloy, or a polyurea-polyurea/urethane alloy on a porous support layer by synthesizing the polymer in a dispersing solvent thereby producing a dispersion-suspension of the polymer in the dispersing solvent which does not dissolve the porous support layer, the polymer being present in the dispersion-suspension at a concentration of from about 0.5 to about 10% polymer, depositing a layer of the dispersion-suspension on one face of the porous support layer, and permitting the dispersing solvent to either evaporate from the dispersion-suspension layer or permeate through the porous support layer, thereby depositing the thin film of a thickness 2 microns or less on the support layer.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the dispersion solvent is selected from 1,4-dioxane, cellosolve acetate, ttrahydrofuran, ketones and aromatic hydrocarbons.
Claim 4
Dependent Claim
22 words
The method of claim 2 wherein the porous support layer is selected from polyamide, polyimide, polyacrylonitrile, polybenzimidazole, cellulose acetate, tefton, and polyolefins.
Claim 5
Dependent Claim
76 words
The method of claim 1 wherein the polyurea/urethane copolymer thin active layer of the thin film composite membrane is characterized by possessing a urea index of at least about 20% but less than 100%, an aromatic carbon content of at least about 15 mole percent, a functional group density defined as the total of C═O and NH per 1000 grams of polymer is greater than about 10 and a C═O/NH ratio of less than about 8.
Claim 6
Dependent Claim
31 words
The method of claim 1 wherein the polyurea thin active layer of the thin film composite membrane is characterized by possessing a total aromatic carbon content of about 86% or less.
Claim 7
Dependent Claim
29 words
The method of claim 1 wherein the polyurea-polyurethane alloy thin active layer of the thin film composite membrane is characterized by possessing about 5 to 95 wt % polyurea.
Claim 8
Dependent Claim
99 words
The method of claim 1 wherein the polyurea-polyurea/urethane alloy thin active layer of the thin film composite membrane is characterized by possessing a ratio of polyurea polymer to polyurea/urethane copolymer in the range of 10 to 90 and the polyurea/urethane copolymer is characterized by possessing a urea index of at least about 20% but less than 100%, an aromatic carbon content of at least about 15 mole percent, a functional group density defined as the total of C═O and NH per 1000 grams of polymer is greater than about 10 and a C═O/NH ratio of less than about 8.
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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) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |