Henkel Ag & Company, Kgaa

Kurita Water Industries Ltd.

Bk Giulini Gmbh

Andreas Arnold

Frank Janssen

Marcel Roth

Matthias Schweinsberg

Michael Wolpers

Konstantinos Markou

Uta Sundermeier

Ard De Zeeuw

Christian Rosenkranz

Jürgen Stodt

Wolfgang Hater

Volker Geick

Klaus Lepa

Stefan Stumpe

Todd Bryden

Ramona Oliva

Steve DÖRING

Paolo Gomes

Pavel Gentschev

The present invention relates to a method for providing electrically insulating and anti-corrosive coatings on electrical steel strip by using a phosphate-free aqueous dispersion. Furthermore, the invention relates to such an aqueous dispersion which is particularly suitable for providing electrically insulating and anti-corrosive coatings on electrical steel strip. The aqueous dispersion of the present invention is substantially free of phosphates and organic compounds and comprises silicates dissolved in water as an inorganic binder which forms the coating, and a mixture of oxide pigments of the elements titanium and aluminum. The subject matter of the invention also comprises a laminated electrical steel strip which is made from the electrical steel strip produced in the method according to the invention or from electrical steel strip coated with an aqueous dispersion according to the invention.

Chromium- and phosphate-free coating for electrically insulating an electric strip

The invention relates to a wet-chemical pretreatment of zinc surfaces prior to applying a corrosion-protection coating, which deposits a thin inorganic coating of oxide and/or metallic iron. An iron layer structure which is applied according to the invention, hereinafter referred to as ferrization, improves the achievable corrosion protection of wet-chemical conversion coatings on zinc surfaces. Furthermore, the ferrization process causes both a reduction of the contact corrosion of joined metal components which have zinc and iron surfaces as well as a reduction of corrosive coating migration on cut edges of galvanized steel strips with coating layer structures. In particular, the invention relates to an alkaline composition containing an iron ion source, a reducing agent based on oxoacids of nitrogen and phosphorus, and water-soluble organic carboxylic acids with an amino group at the &#x3b1;, &#x3b2;, or &#x3b3; position with respect to the acid group and/or the water-soluble salts thereof.

Pretreating zinc surfaces prior to a passivating process

The invention relates to an at least two-stage method for corrosion protection treatment of metal surfaces, wherein, in a first step (i), an organic coating comprising an aqueous phase (A) is applied to the metal surface and, in a following step (ii), the organic coating applied to the metal surface contacted with an acidic, aqueous composition (B) comprising at least one or more water-soluble compounds containing at least one atom selected from the elements Zr, Ti, Si, Hf, V and/or Ce and one or more water-soluble compounds that release copper ions. The invention further comprises a metal component that is at least partially made of steel, iron, zinc and/or aluminum and the alloys thereof and has been treated by the method according to the invention, and to the use thereof in automobile construction and in the construction industry and for producing household appliances and electronics housings.

Two-stage method for the corrosion protection treatment of metal surfaces

The present invention relates to a method for the metallizing pretreatment of galvanized and/or alloy-galvanized steel surfaces or joined metallic components having at least some zinc surfaces, wherein a thin surface layer of iron is deposited on the zinc surfaces from an aqueous electrolyte containing water-soluble compounds that are a source of iron cations. The method is performed at least partially or continuously under application of an electrolytic voltage, the galvanized and/or alloy-galvanized steel surfaces being connected as cathode. The aqueous electrolyte additionally contains an accelerator selected from oxo acids of the elements phosphorus, nitrogen and/or sulfur, the elements phosphorus, nitrogen and/or sulfur being present in moderate oxidation states.

Electrolytic iron metallizing of zinc surfaces

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Hilden, Germany

Andreas Arnold