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US 4,243,701 AGranted
Preparation of gas separation membranes
AssigneeUop LLC
InventorsRobert L. Riley, Richard L. Grabowsky
Life of this patent
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AssigneeUop LLC
InventorsRobert L. Riley, Richard L. Grabowsky
Estimating the term…
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.degree. to about 150.degree. C. to form the desired membrane.
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.
Dependencies are inferred from the claim text.