Bernard, Rothwell & Brown
Process for preparing polyimides
 A process for making certain polyimides involves dissolving substantially equimolar amounts of an aromatic dianhydride and an organic diamine in a high-boiling, aprotic solvent, heating the reaction solution to form an insoluble polyimide prepolymer and to distill out water of reaction, separating the solid polyimide prepolymer and melt polymerizing the polyimide prepolymer to form the desired polyimide. 
General Electric Company
C C
C08G C08G
inventional inventional
Patrick E. Ronald A.
Gallagher Greenberg