Abstract: Binders for cathodic electrocoating which are water-dilutable on protonation with acids contain(A) from 50 to 95% by weight of a polymerization, polycondensation or polyaddition product having an average molecular weight of from 200 to 20,000, primary and/or secondary hydroxyl groups, primary, secondary and/or tertiary amino groups and an amine number of from 30 to 150 and(B) from 5 to 50% by weight of a mixture of(a) blocked polyisocyanates and/or urea condensation products and(b) one or more phenolic Mannich bases obtainable from(b.sub.1) one or more polycyclic polyphenols,(b.sub.2) formaldehyde or a formaldehyde-donating compound and(b.sub.3) one or more secondary aliphatic amines.

Abstract: Cathodic electrocoating binders which are water-dilutable on protonation with an acid are obtainable by reactingA) an epoxy compound or a mixture of epoxy compounds having an epoxide equivalent weight of less than 2,000 withB) a compound which is monofunctional with respect to epoxides and contains aliphatic or phenolic OH groups andC) a secondary amine of 2 to 36 carbon atoms, with the proviso that the reaction product of A), B) and C) still contains free epoxy groups, andD) an amount of an amidoamine containing primary amino groups which is equivalent to or greater than the amount of these free epoxy groups, the said amidoamine being obtainable from a primary diamine and a mono- and/or dicarboxylic acid.

Abstract: Heat-reactive crosslinking agents for surface coating binders, based on phenolic Mannich bases, are obtainable by reacting(A) one equivalent of a polyphenol with(B) from 0.5 to 2 equivalents of formaldehyde or of a formaldehyde-donating compound and(C) from 0.5 to 1 equivalent of one or more secondary aliphatic amines,removing the water of reaction and reacting the resulting reaction produce with(D) from 0.01 to 1 equivalent of a mono- and/or polyfunctional isocyanate compound.

Abstract: A heat-curable coating material for cathodic electrocoating is water-dilutable on protonation with an acid and contains(A) from 50 to 95% by weight of a polymer, polycondensate or polyadduct containing primary and/or secondary amino groups, as a binder, and(B) from 5 to 50% by weight of a crosslinking agent obtainable by reacting(a) a polyurethane with(b) formaldehyde or a formaldehyde-donating compound and(c) one or more secondary aliphatic amines.