Separation membrane

Abstract

Abstract PURPOSE:To obtain a membrane having a high gas permeating velocity while maintaining excellent selectivity in the separation of a gaseous mixture by using a membrane material consisting essentially of copolyimide. CONSTITUTION:The membrane consists essentially of copolyimide having a repeating unit structure shown by the formula I whose 10-50mol% consists of the unit having R shown by the formula II and the remaining part of the unit having R shown by the formula III. Polyacid amide is firstly obtained to manufacture the copolyimide. The copolyimide is manufactured by allowing to react for example, benzophenone-3,3' and 4,4'-tetracarboxylic acid dianhydride with 4,4'- methylene bis(phenyl isocyanate) and toluene diisocyanate (2,4-isomer or 2,6- isomer or the mixture thereof) in an appropriate molar ratio in the presence of a bipolar neutral solvent.

Inventors

• 👤 Munehisa Okada
• 👤 宗久 岡田
• 👤 Takayuki Oota
• 👤 太田　隆之

Bibliographic Details