Patent attributes
A thermosetting composition comprising (a) 97.9 to 40 percent by weight of at least one bis(dihydrobenzoxazine) prepared by the reaction of an unsubstituted or substituted bisphenol with at least one unsubstituted position ortho to each hydroxyl group, formaldehyde and a primary amine; (b) 2 to 50 percent by weight of at least one organic polyamine; and (c) 0.1 to 10 percent by weight of at least one curing catalyst, selected from the group of carboxylic acids, sulfonic acids and phosphonic acids having at least two acid groups and no other reactive groups; wherein the percent by weight refer to the total amount of components (a), (b) and (c) in the composition, with the proviso that (a), (b) and (c) add up to 100 percent by weight; and (d) and optionally other components. Cured products of these compositions show valuable chemical, physical and mechanical properties.