Basf Aktiengesellschaft

Gunther Sabelus

Eberhard Schupp

Fritz E Kempter

Harro Petersen

Wolfram Weiss

Horst Schmidt

The heat-curable coating agent according to the invention contains a combination of a binder, which possesses basic nitrogen groups and is rendered water-dilutable by protonation with an acid, and a crosslinking agent and, if required, pigments, fillers, corrosion inhibitors, surface coating assistants and catalysts, and the binder used is a reaction product of a dicarboxylic acid or of a dicarboxylate or of a (meth)acrylate oligomer or polymer with an adduct of a di- or triglycidyl ether and a polyamine, the polyamine containing 2 or more amine nitrogen atoms per molecule and one or more alkylene chains of 3 or more carbon atoms between the amino groups, and has an NH amine number of from 50 to 150 mg of KOH/g and is combined with aminoplasts and/or phenoplasts as crosslinking agents. The novel coating agent is useful as a binder for the cathodic electrocoating of metal articles.

Heat-curable coating agent and its use

Amide-containing epoxy resin/amine adducts are prepared by a process in which an epoxy resin/amine adduct containing primary and/or secondary aminoalkyl groups is reacted with a carboxylic acid in the presence of esterification catalysts, particularly advantageously in the presence of an alcohol. The products prepared according to the invention are useful as binders for cathodic electrocoating.

Preparation of amide-containing epoxide/amine adducts

A bath composition for cataphoretic electrocoating of conductive surfaces contains coating agents which have been rendered soluble or dispersible with acid, contain basic nitrogen groups and carry groups of the general formulae (1) and (11) ##STR1## and, optionally, also groups of the general formulae (III) and/or (IV) ##STR2## where R.sup.1 and R.sup.2 are each alkyl, hydroxyalkyl or alkoxyalkyl, R.sup.3 and R.sup.4 are each hydrogen or methyl, R.sup.5 and R.sup.6 are each hydrogen, alkyl or a divalent radical of a polymer molecule which is bonded to a phenol or phenol ether, n.sup.1 is 1, 2 or 3 and n.sup.2 is 1 or 2, and where the oxygen bonded to the phenyl radical is either in the form of the OH group or etherified.

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Lambsheim, Germany

Gunther Sabelus