US4556530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a very thin dense membrane
Assignee: Shell USA Inc
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Filing: 1984-07-26
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Granted: 1985-12-03
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Expires: 2004-07-26
Abstract
Abstract A very thin, dense membrane is produced by preparing a solution of a polymer and/or prepolymer and a substantially water insoluble surface active agent in an organic liquid, allowing the solution to spread spontaneously on the surface of a liquid support substantially consisting of a polar fluid and allowing the solution to desolvate and to react, if a prepolymer is present. The membrane so produced may be supported by a substrate comprising at least one porous layer.
Inventors
- 👤 Albert van der Scheer
- 👤 Marinus J. Reynhout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:13
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/122
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
89 words
A process for producing a very thin, dense membrane which comprises (1) preparing a solution of a base polymer or a base prepolymer and a substantially water insoluble surface active agent in an organic liquid, (2) allowing the solution to spread spontaneously on the surface of a liquid support substantially consisting of a polar fluid and allowing the solution to desolvate and to react, if a prepolymer is present, thereby effecting the formation of a very thin dense membrane comprising said polymer and said water insoluble surface active agent.
Claim 2
Dependent Claim
89 words
A process for producing a very thin, dense membrane which comprises (1) preparing a solution of a base polymer or a base prepolymer and a substantially water insoluble surface active agent in an organic liquid, (2) allowing the solution to spread spontaneously on the surface of a liquid support substantially consisting of a polar fluid and allowing the solution to desolvate and to react, if a prepolymer is present, thereby effecting the formation of a very thin dense membrane comprising said polymer and said water insoluble surface active agent.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the polar fluid substantially consists of water.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the surface agent is a dispersant.
Claim 5
Dependent Claim
23 words
The process of claim 3 wherein the surface active agent is a product prepared by reacting a polyalkenyl-substituted succinic anhydride with a polyalcohol.
Claim 6
Dependent Claim
15 words
The process of claim 4 wherein the surface active agent is polyisobutylene maleic anhydride polyalcohol.
Claim 7
Dependent Claim
23 words
The process of claim 3 wherein the surface active agent is a product prepared by reacting a polyalkenyl-substituted succinic anhydride with a polyalkyleneamine.
Claim 8
Dependent Claim
15 words
The process of claim 6 wherein the surface active agent is polyisobutylene maleic anhydride polyalkyleneamine.
Claim 9
Dependent Claim
16 words
The process of claim 1 wherein the base polymer or the base prepolymer is an organosiloxane.
Claim 10
Dependent Claim
11 words
The process of claim 8 wherein the base polymer is dimethylsiloxane.
Claim 11
Dependent Claim
11 words
The process of claim 8 wherein the base prepolymer is dimethylsiloxane.
Claim 12
Dependent Claim
13 words
The process of claim 1 wherein the organic solvent is a hydrocarbon solvent.
Claim 13
Dependent Claim
18 words
The process of claim 11 wherein the hydrocarbon solvent has from one to ten carbon atoms per molecule.
Claim 14
Dependent Claim
10 words
The process of claim 12 wherein the solvent comprises 2,2,4-trimethylpentane.
References Cited (Backward Citations)
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US4132824A
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US4155793A
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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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |