Patent US4243701A successfully refreshed from Google Patents.
US4243701A
Expired / Lapsed
US
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Preparation of gas separation membranes
Assignee: Honeywell UOP LLC
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Filing: 1979-11-08
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Granted: 1981-01-06
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Expires: 1999-11-08
Abstract
Abstract Membranes, which may be used for the separation of gases, comprise a thin film of a semi-permeable material composited on a porous support member. The membranes are prepared by passing a support member through a solution of a halogenated hydrocarbon solvent containing a semi-permeable membrane forming prepolymer and cross-linking agent. This step is then followed by the cross-linking of the prepolymer by treatment at an elevated temperature. The process may be exemplified by passing one finely porous surface of a cellulose nitrate-cellulose acetate support member through a solution of dimethyl silicone in a halogenated solvent such as trifluorotrichloroethane followed by treatment at a temperature in the range of from about 50° to about 150° C. to form the desired membrane.
Inventors
- 👤 Robert L. Riley
- 👤 Richard L. Grabowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:16
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D2323/00; B01D2323/08; B01D2323/081; B01D2323/12; B01D2323/30; Y; Y10; Y10S; Y10S264/00; Y10S264/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A process for the production of a membrane for the separation of gases which comprises forming a thin film of a non-porous semi-permeable membrane selectively permeable to glass having a thickness in the range of from about 250 Angstroms to about 10,000 Angstroms directly on the surface of a porous support member by passing one finely porous surface of said porous support member through a solution of a halogenated hydrocarbon solvent containing a semi-permeable membrane forming prepolymer and a cross-linking agent, withdrawing the coated porous support member from said solution, and thereafter cross-linking said prepolymer by treatment at an elevated temperature to form the resultant membrane comprising said porous support member coated with a thin film of a semi-permeable membrane.
Claim 2
Dependent Claim
120 words
A process for the production of a membrane for the separation of gases which comprises forming a thin film of a non-porous semi-permeable membrane selectively permeable to glass having a thickness in the range of from about 250 Angstroms to about 10,000 Angstroms directly on the surface of a porous support member by passing one finely porous surface of said porous support member through a solution of a halogenated hydrocarbon solvent containing a semi-permeable membrane forming prepolymer and a cross-linking agent, withdrawing the coated porous support member from said solution, and thereafter cross-linking said prepolymer by treatment at an elevated temperature to form the resultant membrane comprising said porous support member coated with a thin film of a semi-permeable membrane.
Claim 3
Dependent Claim
25 words
The process as set forth in claim 1 in which said elevated temperature is in a range of from about 50° to about 150° C.
Claim 4
Dependent Claim
16 words
The process as set forth in claim 1 in which said halogenated hydrocarbon solvent is trifluorotrichloroethane.
Claim 5
Dependent Claim
15 words
The process as set forth in claim 1 in which said prepolymer is dimethyl silicone.
Claim 6
Dependent Claim
16 words
The process as set forth in claim 1 in which said prepolymer is a silicone-carbonate copolymer.
Claim 7
Dependent Claim
14 words
The process as set forth in claim 1 in which said prepolymer is styrene.
Claim 8
Dependent Claim
20 words
The process as set forth in claim 1 in which said porous support member is a cellulose nitrate-cellulose acetate membrane.
Claim 9
Dependent Claim
18 words
The process as set forth in claim 1 in which said porous support member is a polysulfone membrane.
Claim 10
Dependent Claim
29 words
The process as set forth in claim 1 in which said membrane is treated with a halogenated hydrocarbon solvent subsequent to said cross-linking step to increase the permeability thereof.
Claim 11
Dependent Claim
14 words
The process as set forth in claim 9 in which said solvent is trifluorotrichloroethane.
Claim 12
Dependent Claim
22 words
The process as set forth in claim 1 in which said polymer chains resulting from said cross-linking step form an amorphous film.
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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) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |