Patent US4806189A successfully refreshed from Google Patents.
US4806189A
Expired / Lapsed
US
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Composite fluid separation membranes
Assignee: Permea Inc
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Filing: 1984-08-13
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Granted: 1989-02-21
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Expires: 2004-08-13
Abstract
Abstract A composite fluid separation membrane having improved fluid permeabilities and a method for preparing same are disclosed. The composite fluid separation membrane is comprised of a porous support in the form of a flat sheet, tube or hollow fiber which is impregnated with a volatile solvent followed by the in situ formation of a separating layer wherein the preimpregnation of the pores of the porous support with the solvent provide a separating layer of substantially uniform thickness and minimum intrusion of the separating layer polymer into the pores of the porous support.
Inventors
- 👤 Menahem A. Kraus
- 👤 Chinh N. Tran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:42
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/1213; B01D67/00; B01D67/0002; B01D67/0009; B01D69/02; B01D69/10; B01D69/1216; B01D71/00; B01D71/06; B01D71/76; B01D2323/00; B01D2323/219; B01D2323/66
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
95 words
A process for forming a composite fluid separation membrane comprising: (a) impregnating a preformed porous support having pores extending there through with a volatile solvent; (b) forming in situ a separating layer on one or both surfaces of the porous support from a solution of a polymer having fluid separation capabilities; (c) evaporating the impregnation solvent while simultaneously evaporating the separating layer polymer solution solvent, the evaporation occurring before substantial diffusion of the separating layer polymer into the pores of the porous substrate; and (d) achieving a composite fluid separation membrane having improved permeability rates.
Claim 2
Dependent Claim
95 words
A process for forming a composite fluid separation membrane comprising: (a) impregnating a preformed porous support having pores extending there through with a volatile solvent; (b) forming in situ a separating layer on one or both surfaces of the porous support from a solution of a polymer having fluid separation capabilities; (c) evaporating the impregnation solvent while simultaneously evaporating the separating layer polymer solution solvent, the evaporation occurring before substantial diffusion of the separating layer polymer into the pores of the porous substrate; and (d) achieving a composite fluid separation membrane having improved permeability rates.
Claim 3
Dependent Claim
41 words
The process for forming a composite fluid separation membrane according to claim 1 wherein the impregnating solvent is comprised of a solvent having a solubility parameter within about ±2 of the solubility parameter of the polymer which forms the separating layer.
Claim 4
Dependent Claim
26 words
The process for forming a composite fluid separation membrane according to claim 1 wherein the rapid evaporation is achieved within 1 second to about 5.0 minutes.
Claim 5
Dependent Claim
36 words
The process for forming a composite fluid separation membrane according to claim 1 wherein the impregnation solvent and the solvent of the separating polymer solution have boiling point ranges which differ by less than 50° C.
Claim 6
Dependent Claim
33 words
The process for forming a composite fluid separation membrane according to claim 1 wherein the impregnation solvent has a boiling point ranging from about 40° C. to about 100° C. at atmospheric pressure.
Claim 7
Dependent Claim
91 words
A process for forming a composite fluid separation membrane comprising: (a) impregnating a preformed porous support having pores extending there through with a volatile solvent; (b) forming in situ an intermediate layer on one or both surfaces of the porous support from a solution of a polymer having high permeabilities for fluid separations; (c) evaporating the impregnation solvent simultaneously with the evaporation of the intermediate layer solution polymer solvent; (d) forming in situ a separating layer on the intermediate layer; and (e) achieving a composite fluid separation membrane having improved permeability.
Claim 8
Dependent Claim
91 words
A process for forming a composite fluid separation membrane comprising: (a) impregnating a preformed porous support having pores extending there through with a volatile solvent; (b) forming in situ an intermediate layer on one or both surfaces of the porous support from a solution of a polymer having high permeabilities for fluid separations; (c) evaporating the impregnation solvent simultaneously with the evaporation of the intermediate layer solution polymer solvent; (d) forming in situ a separating layer on the intermediate layer; and (e) achieving a composite fluid separation membrane having improved permeability.
Claim 9
Dependent Claim
68 words
A process for forming an ultrathin encapsulation membrane for encapsulating materials supported on porous support, comprising: (a) impregnating the supported materials and the supporting porous support with a solvent; and (b) forming an in situ encapsulation membrane from a solution of polymer of the encapsulation membrane, the in situ formation occurring as a result of simultaneous evaporation of the impregnation solvent and the solvent of the polymer solution.
Claim 10
Dependent Claim
68 words
A process for forming an ultrathin encapsulation membrane for encapsulating materials supported on porous support, comprising: (a) impregnating the supported materials and the supporting porous support with a solvent; and (b) forming an in situ encapsulation membrane from a solution of polymer of the encapsulation membrane, the in situ formation occurring as a result of simultaneous evaporation of the impregnation solvent and the solvent of the polymer solution.
Claim 11
Dependent Claim
28 words
The process for forming an ultrathin encapsulation membrane according to claim 7 wherein the material is selected from the group consisting of catalyst, herbicides, medications, fertilizers, and enzymes.
Claim 12
Dependent Claim
65 words
A process for forming an ultrathin encapsulation membrane for encapsulating a porous material, comprising: (a) impregnating the pores of the material with a solvent; (b) forming in situ an encapsulation membrane of the surface of the porous material from a solution of a polymer which forms the membrane as a result of simultaneous evaporation of the impregnation solvent and the solvent of the polymer solution.
Claim 13
Dependent Claim
65 words
A process for forming an ultrathin encapsulation membrane for encapsulating a porous material, comprising: (a) impregnating the pores of the material with a solvent; (b) forming in situ an encapsulation membrane of the surface of the porous material from a solution of a polymer which forms the membrane as a result of simultaneous evaporation of the impregnation solvent and the solvent of the polymer solution.
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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) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |