SOLUBLE POLYIMIDES BASED ON BIS(O-PHENYLE NEDIAMINE)S

N-Phthalimido-substituted polyimides soluble in organic solvents were prepared by reaction of bis(o-phenylenediamines), which are the best k now chloral derivatives, with bis(phthalic anhydride)s folio wed by th e reaction with phthalic anhydride and catalytic imidization of the sy nthesized prepolymers. Polyimides combine high thermal stability and f ire-resistance with good processibility and capability of forming cros s-linked structures upon heating.