Verfahren zur Herstellung carboxyl- und hydroxylgruppenhaltiger Polyesterimide und deren Verwendung in Drahtlacken

摘要

The invention relates to a method for the production of polyester imide resins containing hydroxyl- and carboxyl groups, comprising as monomer components: (A) imide-forming compounds with at least two primary amino groups and/or at least two isocyanate groups or imide-forming compounds with at least one primary amino group and/or at least one isocyanate group and at least one further functional group selected from hydroxy-, carboxy- and/or carboxylic acid anhydride, (B) polycarboxylic acids and/or their anhydrides and/or their esters; and (C) polyols, characterized in that (I) the (A) component is reacted with part of the (B) component to form a polyimide; (II) the polyimide obtained in accordance with step (I) is reacted with the (C) component to form a polyester imide; and finally (III) the polyester imide obtained in accordance with step (II) is reacted with the remaining part of the (B) component giving the polyester imide containing hydroxyl- and carboxyl groups. Furthermore, the invention comprises the use of the polyester imides produced by this method as binding agents and wire enamels, containing polyester imides with hydroxyl- and carboxyl groups with an acid number >80 mg KOH/g, which can be produced by the method given in this invention.