Condensates based on substituted ureas, their reaction products with di- and/or polyisocyanates, derivatives of di- and/or polycarboxylic acids or p-substituted phenols and/or their methylol derivatives, their preparation and their use. These condensates each contain two or more cyclic urea units and can be prepared either by reacting primary di- or polyamines with ureas and reacting the product with predominantly CH-acidic aldehydes or by reacting primary amines with isocyanates and reacting the product with predominantly CH-acidic aldehydes in the presence of an acidic catalyst. The said condensates and their reaction products are useful for the preparation of heat-curable coating materials and of binders for cathodic electrocoating.