| abstract |
Diamines and carboxylic dianhydrides for polymerizing polyimides containing hexafluoroisopropylidene groups have limitations in their chemical structure when used as polyimide membranes. There was a problem that it was difficult to design the structure. The gas separation membrane which is easy to melt | dissolve in an organic solvent, is excellent in moldability, is easy to use as a gas separation membrane, and is excellent in gas separation performance is obtained. In general formula (1): (61) (In formula (1), R < 1> is a divalent organic group and R < 2> is a tetravalent organic group, and R < 1> is a 2-hydroxy-1,1,1,3,3,3-hexafluoroisopropyl group. A gas separation membrane containing a polyimide comprising a repeating unit represented by: (including -C (CF 3 ) 2 OH).). |