Polyimide, polyimide powder, polyimide coatings, and polyimide films

Abstract

The objective of this invention is to provide polyimide and its powder, as well as coatings using the polyimide, which can form polyimide films with excellent heat resistance, transparency, and mechanical properties, and are soluble in organic solvents and have excellent compatibility with compounds having reactive functional groups. The present invention provides a polyimide synthesized from a diamine compound and a tetracarboxylic dianhydride, characterized in that the aforementioned polyimide comprises: constituent units derived from (a) the diamine compound shown in Formula 1, (b) the carboxyl-containing diamine compound shown in Formula 2, and (c) 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (Formulas 1 and 2 are as defined in this specification), wherein the amount of constituent units derived from (a) is 60-95 mol% relative to the total mol% of constituent units derived from the diamine compound, and the amount of constituent units derived from (b) is 5-30 mol%, and the amount of constituent units derived from (c) is mol% or more relative to the total amount of constituent units derived from the tetracarboxylic dianhydride.