Method of manufacturing a polyimide-type gas permeation membrane including fluorine
AssigneeNitto Denko Corporation
InventorsHisao Hachisuka, Ping Xu, Tomomi Ohara
Life of this patent
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Abstract
Polyimide resin dope having at least three fluorine atoms in a repeating molecular unit and an organic solvent (A) are extruded in a tube form or coating the dope on a supporting body. The polyimide resin dope is then immersed in a solvent (B), which the organic solvent (A) is miscible with the solvent (B). Thus, a polyimide-type gas separation membrane including fluorine is virtually defect free in the skin layer, and manufactured cost-effectively by a simple manufacturing method.
Claims16
A method of manufacturing a fluorine including polyimide-type gas separation membrane comprising the steps of:
- extruding a polyimide dope which consists of a fluorine including polyimide resin and an organic solvent (A) in a tube form;
- or coating said dope on a supporting body;
- and
- immersing the extruded tube or the coated supporting body in a solvent (B) to form a membrane;
- wherein said fluorine including polyimide resin comprises at least three fluorine atoms in a repeating molecular unit;
- wherein said organic solvent (A) comprises at least two ether bonds in a repeating molecular unit;
- and wherein said organic solvent (A) is miscible with said solvent (B).
A method of manufacturing a fluorine including polyimide-type gas separation membrane comprising the steps of:
- extruding a polyimide dope which consists of a fluorine including polyimide resin and an organic solvent (C) in a tube form;
- or coating said dope on a supporting body;
- and
- immersing the extruded tube or the coated supporting body in a solvent (B) to form a membrane;
- wherein said fluorine including polyimide resin comprises at least three fluorine atoms in a repeating molecular unit;
- wherein said organic solvent (C) has a dielectric constant less than 30 and a dipole moment less than 3.0D;
- and wherein said organic solvent (C) is miscible with said solvent (B).
Dependencies are inferred from the claim text.