Patent EP0141793A1 successfully refreshed from Google Patents.
EP0141793A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Asymmetric gas separation membranes having increased selectivy, and process for their production
Assignee: Monsanto Co
•
Filing: 1984-06-28
•
Granted: —
•
Expires: 2004-06-28
Abstract
Abstract Asymmetric gas separation membranes of polymeric materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit improved permeation selectivities for the at least one gas when the symmetric membranes are contacted on one or both surfaces with an effective amount of a solvent, the solvent having a solubility parameter similar to the solubility parameter of the polymeric materials comprising the membranes. The improved asymmetric gas separation membranes, process for producing the improved membranes, and processes for utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.
Inventors
- 👤 Harry Philip Holladay
- 👤 Maurice Lucien Woodcock
- 👤 Robert Roch Ward
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 19:08
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
84 words
An asymmetric gas separation membrane exhibiting substantially improved gas separation selectivity comprising: a preformed asymmetric gas separation membrane of polymeric material having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture which has been contacted on one or both surfaces with a solvent, the solvent having a solubility parameter within about plus or minus 2 of the solubility parameter of the polymeric material which comprises the asymmetric gas separation membrane.
Claim 2
Dependent Claim
84 words
An asymmetric gas separation membrane exhibiting substantially improved gas separation selectivity comprising: a preformed asymmetric gas separation membrane of polymeric material having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture which has been contacted on one or both surfaces with a solvent, the solvent having a solubility parameter within about plus or minus 2 of the solubility parameter of the polymeric material which comprises the asymmetric gas separation membrane.
Claim 3
Dependent Claim
29 words
The improved asymmetric gas separation membrane of Claim 1 wherein the separation factor for the one gas of the gas mixture is increased by at least 100% or greater.
Claim 4
Dependent Claim
37 words
The improved asymmetric gas separation membrane of Claim 2 wherein the improvement in separation factor for the one gas of the gas mixture is accomplished with a reduction of permeability rate of not more than about 50%.
Claim 5
Dependent Claim
28 words
The improved asymmetric gas separation membrane of Claim 1 wherein the solvent is selected from the group consisting essentially of alcohols, aromatics, halogenated hydrocarbons, ketones, esters, and plasticizers.
Claim 6
Dependent Claim
16 words
The improved asymmetric gas separation membrane of Claim 1 wherein the solvent is selected from alcohols.
Claim 7
Dependent Claim
24 words
The improved asymmetric gas separation membrane of Claim 5 wherein the alcohol solvents have from 1 to 6 or less carbon atoms per molecule.
Claim 8
Dependent Claim
37 words
The improved asymmetric gas separation membrane of Claim 1 wherein the solvent has a solubility parameter within plus or minus 1 of the polymer solubility parameter, the polymers being selected from the group consisting essentially of polyethers.
Claim 9
Dependent Claim
34 words
The improved asymmetric gas separation membrane of Claim 1 wherein both the solvent and the polymer have solubility parameters equal to or greater than about 9 and equal to or less than about 12.
Claim 10
Dependent Claim
26 words
The improved asymmetric gas separation membrane of Claim 1 wherein the solvent contains from about 0.3% to about 5.0% of a compound which retards membrane densification.
Claim 11
Dependent Claim
16 words
The improved asymmetric gas separation membrane of Claim 1 wherein the compound is comprised of siloxanediols.
Claim 12
Dependent Claim
125 words
A process for improving the selectivity of an asymmetric gas separation membrane of polymeric material exhibiting selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of a gaseous mixture comprising: contacting the preformed asymmetric gas separation membrane with a solvent, the solvent having a solubility parameter of plus or minus 2 of the solubility parameter of the polymeric material which comprises the asymmetric gas separation membrane, the asymmetric membrane being contacted on one or both surfaces with the solvent for periods sufficient with respect to at least one pair of gases to improve the separation factor significantly greater than the separation factor exhibited by the asymmetric membrane before solvent treatment; and removing the residual solvent.
Claim 13
Dependent Claim
125 words
A process for improving the selectivity of an asymmetric gas separation membrane of polymeric material exhibiting selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of a gaseous mixture comprising: contacting the preformed asymmetric gas separation membrane with a solvent, the solvent having a solubility parameter of plus or minus 2 of the solubility parameter of the polymeric material which comprises the asymmetric gas separation membrane, the asymmetric membrane being contacted on one or both surfaces with the solvent for periods sufficient with respect to at least one pair of gases to improve the separation factor significantly greater than the separation factor exhibited by the asymmetric membrane before solvent treatment; and removing the residual solvent.
Claim 14
Dependent Claim
32 words
The process according to Claim 11 wherein the improved asymmetric gas separation membrane is contacted with a solvent selected from the group consisting essentially of alcohols, aromatics, halogenated hydrocarbons, esters, and plasticizers.
Claim 15
Dependent Claim
29 words
The process according to Claim 11 wherein the solvent is contacted with the asymmetric gas separation membrane for a period varying from about 15 seconds to about 30 minutes.
Claim 16
Dependent Claim
23 words
The process according to Claim 11 wherein the solvent is in a vapor state when contacted with the preformed asymmetric gas separation membrane.
Claim 17
Dependent Claim
35 words
The process according to Claim 11 wherein the solvent is in a liquid state when contacted with the preformed asymmetric gas separation membrane and the liquid solvent can be comprised of one or more solvents.
Claim 18
Dependent Claim
27 words
The process according to Claim 11 wherein the material of the preformed asymmetric gas separation membrane is comprised of polymers and copolymers and substituted polymers of polyethers.
Claim 19
Dependent Claim
33 words
The process according to Claim 11 wherein the material of the preformed asymmetric gas separation membrane is comprised of polymers and copolymers and substituted polymers of polysulfone, polyethersulfone, polyphenylene oxide, and styrene-acrylonitrile copolymers.
Claim 20
Dependent Claim
30 words
The process according to Claim 11 wherein the solvent has a solubility parameter within plus or minus 1 of the polymer solubility parameter which comprises the asymmetric gas separation membrane.
Claim 21
Dependent Claim
141 words
A process for improving the selectivity of a multicomponent membrane for gas separations wherein an asymmetric membrane is coated with one or more materials, said multicomponent membrane exhibiting selectivity permeation of at least one gas of a gaseous mixture over that of one or more of the remaining gases of a gaseous mixture comprising: contacting the preformed multicomponent gas separation membrane with an effective amount of a solvent when the solvent has the solubility parameter of within plus or minus 2 of the polymer solubility parameter which comprises the asymmetric membrane portion of the multicomponent membrane, the solvent being contacted on one or both surfaces of the multicomponent membrane for a period sufficient with respect to at least one pair of gases to improve the separation factor significantly greater than the separation factor exhibited by the multicomponent membrane for solvent treatment.
Claim 22
Dependent Claim
141 words
A process for improving the selectivity of a multicomponent membrane for gas separations wherein an asymmetric membrane is coated with one or more materials, said multicomponent membrane exhibiting selectivity permeation of at least one gas of a gaseous mixture over that of one or more of the remaining gases of a gaseous mixture comprising: contacting the preformed multicomponent gas separation membrane with an effective amount of a solvent when the solvent has the solubility parameter of within plus or minus 2 of the polymer solubility parameter which comprises the asymmetric membrane portion of the multicomponent membrane, the solvent being contacted on one or both surfaces of the multicomponent membrane for a period sufficient with respect to at least one pair of gases to improve the separation factor significantly greater than the separation factor exhibited by the multicomponent membrane for solvent treatment.
References Cited (Backward Citations)
DE2110158B2
Cited
DE2750874A1
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.