Aqueous coating composition containing an epoxy-amine system and an aromatic carboxylic acid as curing catalyst

A kit-of-parts, comprising two separate components A) and B):

• A) at least one aqueous base varnish containing at least one aqueous dispersion (A) of an epoxy resin (ER1), said epoxy resin (ER) having on average at least one epoxy group per molecule;
• and
• B) at least one aqueous hardener component containing
• at least one aqueous resin dispersion (B) comprising at least one di- and/or polyfunctional monomeric primary and/or secondary amine (A1) in a proportion by weight of 0.5 to 5% and a resin component (RC) having an NH equivalent of 150 to 400 g/mol, the resin component (RC) comprising at least one polyfunctional organic amine (A2) having primary and/or secondary amino groups, said at least one polyfunctional organic amine (A2) containing the reaction product of:
• (i) at least one di- and/or multifunctional epoxy resin (ER2) having an average epoxy equivalent weight of less than 400 g/mol,
• (ii) at least one di- and/or polyfunctional monomeric primary and/or secondary amine (A3), and
• (iii) at least one compound X—R where X is a functional group reactive towards epoxy groups and R is an organic radical containing at least one polyoxyalkylene unit and not containing further X groups;
• and
• at least one aromatic compound (C) having at least one carboxylic acid group.