Coating solution of polyetherimide oligomers

Claim 1

A process for preparing a coating solution including oligomeric polyetherimides comprising: (a) reacting at least one aromatic bis(ether anhydride of the formula: ##STR12## with less than a stoichometric amount of at least one diamine of the general formula: H.sub.2 N--R.sup.1 --NH.sub.2 in a suitable solvent to form oligomeric polyetheramic acids containing termanal anhydride groups (b) heating the solution of (a) to form oligomeric polyetherimide anhydrides (c) hydrolizing the oligomeric anhydrides of (b) to form the free acids of the formula: ##STR13## (d) adding to the oligomer solution of (c) triamines of the general formula: R.sup.2 (NH.sub.2).sub.3, and more of the same or different diamine, where R is a member selected from the class consisting of (A) divalent organic radicals having the following formulas: ##STR14## and (B) divalent organic radicals of the general formula: ##STR15## where m is 0 or 1 and X is a member selected from the class consisting of divalent radicals of the formulas, ##STR16## where y is an integer from 1 to 4; R 1 is a divalent organic radical selected from the class consisting of (a) aromatic hydrocarbon radicals having from 6 to about 20 carbon atoms and haloginated derivatives thereof, (b) alkylene radicals having from 2 to about 20 carbon atoms, and cycloalkylene radicals having from 3 to about 30 carbon atoms, (c) from C 2 to about C 8 alkylene terminated polydiorganosiloxane, and (d) divalent radicals of the general formula: ##STR17## where m is as previously defined and Q is a member selected from the class consisting of ##STR18## where x is an integer from 1 to 5 inclusive, R 2 is a member selected from the class consisting of (a) the following trivalent aromatic radicals ##STR19## and (b) trivalent aliphatic radicals; ##STR20## and n is an integer from 0 to 100.