Disclosed is an azaoxa heterocyclic compound represented by the following
formula (I): ##STR00001## (wherein, each symbol is defined the same as
in the specification) and a method for preparing the same. This compound
of the present invention is prepared by the reaction of a phenolic
compound, an aromatic diamine compound and an aldehyde compound. The
azaoxa heterocyclic compound of the present invention can be used as a
hardening resin or a hardener for an epoxy resin, polyether and a resin
containing active hydrogen atoms, wherein the composition formed by the
azaoxa heterocyclic compound and the epoxy resin is useful in the
application of laminates, adhesive, semiconductor packaging materials and
phenolic resin forming materials.