Patent ID: 6911490

Claim:
An aqueous curing agent for aqueous epoxy resin dispersions which comprises mixtures, adducts and/or salts of partly esterified phosphoric acids A1 wherein the partly esterified phosphoric acids A1 have an acidic hydrogen atom which is attached directly or via an oxygen atom to phosphorus atom, and at least one group of the kind R—O—P, where R denotes a linear, branched or cyclic alkyl or aryl radical which has from 1 to 20 carbon atoms, and the phosphoric acids are selected from ortho-phosphoric acid H 3 PO 4 , diphosphoric acid H 4 P 2 O 7 , triohosphoric acid H 5 P 3 O 10 , and the higher homologs (oligomers), phosphorous acid H 3 PO 3 , diphosphorous acid H 4 P 2 O 5 , and also the higher homologs thereof, and also hypophosphorous acid H 3 PO 2 , and its higher homologs, with organic amines B containing at least one primary amino group which are selected from the group consisting of epoxide-amine adducts B1, Mannich bases B2, polyaminoamides B3, and condensation products B4 of diamines or polyamines B42 with di- or polyhydroxyaromatics B41, and wherein the proportions of the components A and B are chosen such that the ratio of the amount of substance of the primary amino groups in B to the amount of substance of component A is from 1:0.1 to 1:0.5 mol/mol.