US4605526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing dense membranes
Assignee: Shell USA Inc
•
Filing: 1985-01-25
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Granted: 1986-08-12
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Expires: 2005-01-25
Abstract
Abstract A process for producing dense membranes comprises allowing a solution comprising a polar polymer and/or a polar prepolymer in a polar solvent which is substantially soluble in a polar liquid to spread out over the surface of the polar liquid and allowing the spread out solution to desolvate. The dense membranes can be applied in supported membranes for use in gas separation processes.
Inventors
- 👤 Marinus J. Reynhout
- 👤 Albert van der Scheer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:03
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D69/00; B01D69/12; B01D69/1216; B01D69/122; B01D71/00; B01D71/06; B01D71/54; Y; Y10; Y10S; Y10S55/00; Y10S55/13
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
50 words
A process for producing dense membranes, wherein a solution comprising a polar polymer and/or a polar prepolymer in a polar solvent which is substantially soluble in a polar liquid is allowed to spread out over the surface of the polar liquid and the spread out solution is allowed to desolvate.
Claim 2
Dependent Claim
50 words
A process for producing dense membranes, wherein a solution comprising a polar polymer and/or a polar prepolymer in a polar solvent which is substantially soluble in a polar liquid is allowed to spread out over the surface of the polar liquid and the spread out solution is allowed to desolvate.
Claim 3
Dependent Claim
14 words
The process according to claim 1 wherein a solution of a prepolymer is used.
Claim 4
Dependent Claim
25 words
The process according to claim 2 wherein the prepolymer is obtained by reaction of a polyol with an isocyanate comprising at least two functional groups.
Claim 5
Dependent Claim
13 words
The process according to claim 3 wherein the isocyanate is diphenyl methane diisocyanate.
Claim 6
Dependent Claim
13 words
The process according to claim 3 wherein the polyol is a polyether glycol.
Claim 7
Dependent Claim
17 words
The process according to claim 5 wherein the polyether glycol has a molar weight of from 150-6000.
Claim 8
Dependent Claim
15 words
The process according to claim 1 wherein a solution of a linear polyurethane is used.
Claim 9
Dependent Claim
26 words
The process according to claim 1 wherein the polar solvent comprises an organic compound with of from 1-10 carbon atoms and one or more hetero atoms.
Claim 10
Dependent Claim
13 words
The process according to claim 8 wherein the organic compound is a ketone.
Claim 11
Dependent Claim
13 words
The process according to claim 9 wherein the ketone is methyl ethyl ketone.
Claim 12
Dependent Claim
19 words
The process according to claim 1 wherein the polar liquid is water or an aqueous solution of a salt.
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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) | 1989-08-11 | 1990-02-10 | 1990-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-11 | 1994-02-10 | 1994-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-11 | 1998-02-10 | 1998-08-12 | $7700.00 | Window Closed / Lapsed |