Cathodically electrodepositable surface coating binder

Claim 1

A cathodic electrocoating binder which is based on polyadducts, copolymers of polycondensates possessing basic nitrogen groups in each case, and can be diluted with water when protonated with an acid, wherein the binder comprises a mixture of (A) from 50 to 95 percent by weight of one or more polyadducts, copolymers or polycondensates which possess basic nitrogen groups in each case and (B) from 50 to 5 percent by weight of one or more amideamines obtained by reacting a monocarboxylic acid of 6 to 24 carbon atoms or a dicarboxylic acid of 4 to 48 carbon atoms, or their esters, with a diamine which possesses one primary and one secondary amino group per molecule, the secondary amino group carrying a β-hydroxyalkyl group, with the proviso that component (A) consists of (A 1 ) one or more phenolic Mannich bases, which are obtained from (a) monophenols or polyphenols, (b) one or more secondary amines, each of which possesses one or more hydroxyalkyl groups, or a mixture of a secondary amine of this type with another secondary or primary amine and (c) formaldehyde or a formaldehyde donor, or (A 2 ) one or more polyadducts, copolymers, or polycondensates possessing acrylic, methacrylic or crotonic double bonds which are incorporated via an amide or ester group, some or all of which can be blocked by adduct formation with a secondary amine, or a mixture of (A 1 ) and (A 2 ), and, instead of a mixture of (A) and (B), the reaction product of component (B) with component (A) or with an intermediate of component (A) can also be used.