Abstract: The invention relates to a cathodic electro-dipcoating process, wherein the electro-dipcoating composition used contains a cationic, amine-modified epoxy resin, which is obtainable by reacting(A) a polyepoxide,(B) an amine and(C) an adduct, which is obtainable by . . . (sic)(c1) a polyether- or polyester-polyol,(c2) a polyisocyanate and(c3) a compound which contains at least one hydrogen atom which is reactive towards isocyanate groups and at least one ketimine group in the molecule, and/or(D) a hydrolysis product of (C)with one another in a relative proportion such that 20 to 90% of the epoxy groups of component (A) are reacted with component (B) and the remaining epoxy groups are reacted with component (C) and/or (D), and--if still necessary--at least partially protonating the reaction product thus obtained.

Abstract: Polymeric reaction products useful as additions to electrocoating baths are obtainable fromA. a polyoxyalkylene which has an average molecular weight M.sub.n of from 140 to 10,000 and contains on average from 1.5 to 3.0 primary and/or secondary amino groups andB. a polymer which is based on a conjugated diene, has an average molecular weight M.sub.n of from 250 to 50,000, contains on average from 1.5 to 3.0 epoxy groups per molecule and is obtainable by reacting a hydroxyl- or carboxyl-containing polymer with a glycidyl compound.

Abstract: A heat-curable coating composition for cathodic electrocoating which becomes water-thinnable on protonation with an acid contains(A) 50-95% by weight of a polycondensation or polyaddition product having an average molecular weight of from 500 to 20,000 and containing primary and/or secondary hydroxyl groups and primary, secondary and/or tertiary amino groups, and(B) 5-50% by weight of a crosslinking agent obtainable by reactinga) an aliphatic polyhydroxy compound andb) an aromatic polyhydroxy compound withc) an aliphatic and/or cycloaliphatic polyisocyanate andd) a blocking agent.

Abstract: A two-phase cathodic electrocoat is obtainable by coating an electrically conducting substrate with a mixture containingA) an aqueous cationic dispersion of a polycondensation or polyaddition product,B) an aqueous cationic dispersion of a polycondensation or polyaddition product having a glass transition temperature of from -80.degree. to 20.degree. C., the polymers of dispersions (A) and (B) being mutually incompatible, and C) optionally a crosslinking agent, a pigment paste, auxiliaries and/or additives, and then baking.

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-curable aqueous coating agents for cathodic electrocoating contain(A) an amino-containing polymerization, polycondensation or polyaddition product as a binder which becomes water-dilutable on protonation with an acid,(B) a crosslinking agent and(C) from 0.05 to 10% by weight, based on components (A) and (B), of a monomeric organic complexing agent.

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.