US 12,234,561 B2
Method for the cleaning and/or anti-corrosion pretreatment of a plurality of components comprising zinc-coated (ZM) steel
Ralf Posner, Dormagen (DE); Kristof Wapner, Duesseldorf (DE); Christian Kolt, Duesseldorf (DE); and Silvia Schmidt, Hilden (DE)
Assigned to Henkel AG & Co. KGaA, Duesseldorf (DE)
Filed by Henkel AG & Co. KGaA, Duesseldorf (DE)
Filed on Mar. 12, 2024, as Appl. No. 18/602,395.
Application 18/602,395 is a continuation of application No. PCT/EP2022/075028, filed on Sep. 8, 2022.
Claims priority of application No. 21196358 (EP), filed on Sep. 13, 2021.
Prior Publication US 2024/0263315 A1, Aug. 8, 2024
Int. Cl. C23G 1/19 (2006.01); C23G 3/02 (2006.01)
CPC C23G 1/19 (2013.01) [C23G 3/023 (2013.01)] 18 Claims
 
1. A method for cleaning and/or anti-corrosion pretreatment of a plurality of components in series, in which the components of the series are at least partially composed of zinc-coated (ZM) steel and in which the components of the series each pass through successive method steps i)-iii):
i) bringing the components into contact with an aqueous cleaning solution having a pH greater than 7.0 and containing at least one surfactant;
ii) bringing at least a surface of the zinc-coated (ZM) steel of the components from step i) into contact with an aqueous agent containing at least one builder which comprises a salt of a Lewis acid-base pair in which the Lewis acid is selected from Li+, Na+, K+, Ca2+, Mg2+ or Al3+ and the Lewis base is selected from anions of a polyprotic Brønsted acid, and optionally at least one surfactant, wherein a total concentration of the builders is at least 0.4 mol/kg, but does not exceed 2.0 mol/kg, the aqueous agent having a pH of no greater than 9.5; and
iii) cleaning by bringing the components from step ii) into contact with a further aqueous cleaning solution, and/or anti-corrosion pretreatment by bringing into contact with an aqueous treatment solution of a conversion treatment.