| 摘要 |
PURPOSE:To prepare a hollow yarn membrane having high permeating rate for H2 and high degree of separation of H2 from CO by prepd. a hollow yarn from a mixture of >=2 kinds of polyimide having different structure. CONSTITUTION:Polyimide unit A (Formula I ) consisting of biphenyl tetracarboxylic dianhydride and 4,4'-diaminophenyl ether and polyimide unit B (Formula II) consisting of biphenyl tetracarboxylic dianhydride and 3,5-diaminobenzoic acid are mixed in (90-75):(10-25)(A/B) proportion, and the polyimides mixture is dissolved in a phenolic compd. to obtain 12-15% concn., and a hollow yarn membrane is obtd. from the soln. The phenolic compd. to be used for the solvent is one having <=ca.100 deg.C m.p., and <=ca.300 deg.C b.p. under normal pressure, specifically, phenol, or cresol, but halogenated phenol is particularly preferred.
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