| 摘要 |
PURPOSE:To prepare hollow yarn for gas separation having superior permeability and selectivity for gaseous CO2 by using arom. polyimide obtd. by imidating a polymer prepd. by polycondensing equimolar amt. of arom. tetracarboxylic acid and arom. diamine. CONSTITUTION:A doping liquid is prepd. by dissolving uniformly 7-30wt% arom. polyimide contg. at least 70% recurrent unit expressed by the formula (I) and (II) in a solvent consisting primarily of a phenolic compound. Preferred phenolic compd. is phenol, cresol, xylenol, halogenated phenol, etc., and necessary content thereof is ca.60vol%. Aq. soln. contg. ca.60vol% alcohol or acetone is used as the coagulating liquid for the formation of film by the wet process. Such coagulating liquid is used for performing coagulation at relatively lower temp. (-10-60 deg.C).
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