Nova Patents
EP0447971A3

Gas separation material

Abstract

A novel class of polyimides useful in making semi-permeable membranes for gas separation is synthesized by the reaction of 4,4-[hexafluoroisopropylidene]-bis-[phthalic anhydride] (6FDA) with 3,7-diamino-2,8-dimethyldiphenylenesulfone (AMPS). In lieu of the two methyl groups the diamine may be substituted by H or C₂₋₄ alkyl. Membranes made from the polyimides have high permeability for CO₂ from mixtures containing CO₂ and other gases such as CH₄ and have commercially acceptable selectivity.

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Projected expiry passed 15 March 2011, 15.5 years ago.

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Citations
DocumentRelationOfficeCategoryCited during
EP0265898A2CitesEuropean Patent Office (EPO)YDSearch report
EP0385240A1CitesEuropean Patent Office (EPO)YPSearch report
US4690873ACitesUnited States of AmericaYDSearch report
JOURNAL OF MEMBRANE SCIENCE, vol. 37, (1988), pages 45-62, ELSEVIER SCIENCE PUBLISHERS B.V., Amsterdam, T.H. KIM et al. "Relationship Between Gas Separation Pro- perties and Chemical Structure in a Series of Aromatic Polyimides"Non-patentSearch report