Aqueous electrocoating baths for cathodic plant deposition and processes for their preparation

US4944855A · kind A · utility

Assignee

• Basf Lacke & Farben Aktiengesellschaft · DE

Inventors

• Georg Schon · Everswinkel, DE
• Gunter Ott · Erlangen, DE
• Michael Geist · Munster, DE

Key dates

• Filing date: Sep 23, 1988
• Grant date: Jul 31, 1990
• Expiry date: Sep 23, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G59/50
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to aqueous electrocoating baths for cathodic paint deposition which contain, as cathodically depositable binders, modified epoxide-amine adducts and are prepared by reacting, in the presence of basic amine catalysts, PA0 (1) PA1 (A) polyepoxides with PA1 (B) compounds which contain, per molecule, one or more, preferably 2, hydroxyl groups bonded to aromatic and/or (cyclo)aliphatic molecular fragments, to form epoxide group-containing intermediates, and PA0 (2) by subsequently reacting these intermediates, if appropriate, with further conventional modifiers and finally with PA1 (C) primary and/or secondary (poly)amines or their salts and/or salts of tertiary amines, the resultant reaction products being neutralized with acids, if appropriate, dispersed in an aqueous medium and these dispersions further processed by well-known methods to form electrocoating baths. The electrocoating baths according to the invention are distinguished by the fact that the basic amine catalyst which catalyzes the reaction between the components (A) and (B) is neutralized, prior to further reaction of the intermediates formed from the components (A) and (B), with a Bronsted acid hav…