Manufacturing method of heat-resistant resin and the heat-resistant resin constituent null which uses this heat-resistant

摘要

PURPOSE:To obtain the title heat-resistant resin improved in resistance to wear, heat shock and coolant, for application on enamel wires by introducing a specific amide-imide oligomer into the molecular chain. CONSTITUTION:A reaction is made between (A) a polyisocyanate compound (e.g., tolylenediisocyanate), (B) a tribasic acid anhydride (e.g., trimellitic anhydride), (C) a dibasic acid (e.g., aromatic dibasic acid) and (D) a lactam (e.g., epsilon-caprolactam) at the equivalent ratio of the COOH to isoccyanate group of 0.8-1.2 followed by further reaction of (E) a tribasic acid anhydride at the equivalent ratio of the COOH to isocyanate group of 0.1-0.5 to synthesize an amide- imide oligomer. Said oligomer is then allowed to react, on heating, with (F) an imido acid-forming component or imido acid, acid component and alcohol component, thus obtaining the objective heat-resistant resin. This resin is applied on an electric conductor and baked, thus objective the other objective enamel wire.