Henkel Ag & Company, Kgaa

Basf Coatings Gmbh

Florian Gaspar

Kristof Wapner

Christian Hammer

Konstantinos Markou

The present invention relates to a method for at least partly coating an electrically conductive substrate with an electrocoat material, comprising at least contacting the substrate with an aqueous coating composition (A) as step (1), which is carried out in at least two successive stages (1a) and (1b), i.e., first at an applied voltage in a range from 1 to 50 V (1a), which is applied over a duration of at least 5 seconds, and then in a range from 50 to 400 V (1b), the voltage applied in (1b) being greater by at least 10 V than the voltage applied in (1a), with (A) comprising at least one cathodically depositable binder (A1), at least one organic monocarboxylic or polycarboxylic acid which has no nitrogen atom(s), and/or anions thereof (A3) and trivalent bismuth (A4), with (A3) and (A4) each being present in (A) in an amount such that their stoichiometry to one another allows at least 50 mol % of (A4) to be present in the form of a salt and/or complex of components (A3) and (A4), with the molar fractions of any zirconium ions and aminopolycarboxylic acids present in (A) to be lower by a factor in each case of 100 or of 15, respectively, than the molar fraction of (A4) present in (A); to a use of (A) for at least partly coating the substrate with an electrocoat material; to at least partly coated electrically conductive substrates obtainable by the method; and to articles or components produced from such substrates.

Two-stage method for dip-coating electrically conductive substrates using a Bi (III)-containing composition

The present invention relates to an aqueous coating composition (A) having a pH in a range from 4.0 to 6.5 and comprising at least one cathodically depositable binder (A1), a total amount of at least 130 ppm of Bi, based on the total weight of (A), including at least 30 ppm of Bi in a form (A3) in solution in (A) and optionally at least 100 ppm of Bi in a form (A4) not in solution in (A), and at least one at least bidentate complexing agent (A5) suitable for complexing Bi, (A5) being a compound of the general formula (1) or an anion of this compound, for at least partly coating an electrically conductive substrate with an electrocoat material, to a method for producing (A), to the use of (A) for at least partly coating an electrically conductive substrate with an electrocoat material, to a corresponding coating method, to an at least partly coated substrate obtainable by this method, and to a method for setting and/or maintaining the concentration of component (A3) and/or optionally (A4) in the coating composition (A) during the coating method.

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Solingen, Germany

Florian Gaspar