Aminourethane hardeners, epoxide-based coating media and the use thereof

Aminourethane hardeners suitable for aqueous epoxide-based coating media, obtained by the reaction of

• A) one or more aminourethanes which are obtained by the reaction of
• a) compounds comprising members selected from the group consisting of at least one 2-oxo-1,3-dioxolane group and 2-oxo-1,3-dioxane group, hereinafter denoted as a cyclic carbonate group, with
• b) one or more amines comprising at least one primary amino group, wherein the ratio of the number of cyclic carbonate groups to the number of primary amine groups is 1:10 to 1:1.1, with
• B) one or more water-thinnable epoxide compounds, which are obtained by the reaction of
• c) at least one member selected from the group consisting of one or more polyalkylene polyethers comprising at least one member selected from a primary .alpha.-amino group and a secondary .alpha.-amino group together with an .omega.-terminal alkyl ether group or an .omega.-terminal aryl ether group and one or more polyalkylene polyethers comprising at least one member selected from two primary .alpha.,.omega.-terminal amino groups and two secondary .alpha.,.omega.-terminal amino groups, each with a weight average molecular weight (Mw) of 200 to 20,000, with
• d) one or more epoxide compounds comprising at least two epoxide groups per molecule and an epoxide equivalent weight of 100 to 2000, wherein the ratio of the number of primary and secondary amino groups of component c) to the epoxide groups of component d) is 1:2 to 1:20, and the epoxide equivalent weight of the condensation products obtained from c) and d) is between 150 and 8000, and
• (C) optionally one or more amines which are different from A) and which comprise at least one primary amino group,
• wherein the ratio of the number of primary amino groups of A) and C) to the number of epoxide groups of B) is 2:1 to 20:1.