HARDENER COMPOSITION FOR AQUEOUS EPOXY RESIN BASED COATING COMPOSITIONS, PROCESS FOR ITS PREPARATION AND USE THEREOF

This invention relates to a hardener composition Η for an aqueous epoxy resin based two-pack coating formulation wherein the hardener composition Η comprises reaction products of at least difunctional epoxides H1, at least difunctional hydroxypolyoxyalkylenes Η2, at least difunctional hydroxyaromatic compounds H3, unsaturated fatty acids H42 having acarboxyl functionality of more one which comprise the so-called dimer fatty acids, secondary amines H having additional carbonylimine-blocked primary amino groups, obtained by reaction of amines H51 having at least one primary amino group and at least one secondary amino group 1 with carbonyl compounds H52 which have an aldehyde or ketone carbonyl group, optionally, hydroxy-functional secondary amines H6 having at least one secondary amino group and at least one hydroxyl group, and further optionally, amines H7 having at least one primary, and at least one tertiary amino group, wherein the unsaturated fatty acids H42 are incorporated into the hardener in the form of beta-hydroxy esters, and wherein water is added to liberate the 20 blocked primary amino groups.It also relates to a process for the preparation of the hardener H, to aqueous two-pack coating compositions with an epoxy resin E, and to the use of these coating compositions as first or primer layer to prepare multilayer coatings together with solvent-borne coating compositions for the upper layer.