Polyimide coating compositions based on meta-dialkyldihydrogen pyromellitate and aromatic diamines

摘要

A composition for the application of a planar polymide coating having a glass transition temperature above 300 degrees C. comprises a solution in an anhydrous, aprotic solvent of (+ the reaction product +) of an aromatic diamine and a (- dialkyldihydrogen -) (+ dialkyl +) pyromellitate (+ diacyl chloride +) which (- is more than -) (+ comprises about +) 90% (+ or more +) meta isomer.