Dip-coating method for protecting chromatized or passivated zinc coatings on steel or the like
AssigneeEwald Dörken AG
InventorBurkhard Flamme
Life of this patent
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Abstract
Chromated or passivated (phosphated) zinc and zinc alloy coatings on workpieces are provided with a protective coating which is largely inorganic and formed from titanium or zirconium chelate and/or titanium or zirconium acid ester and an organofunctional polysiloxane applied in solution form by a post-treatment dipping.
Claims6
A steel workpiece having a chromated or passivated zinc or zinc alloy coating having a protective coating thereon formed by
- (a) dipping a steel workpiece having a chromated or passivated zinc or zinc-alloy coating in a solution of a binder composition in a solvent system wherein said binder composition and solvent system are selected from the group which consists of:
- (1) a binder composition consisting essentially of at least one titanium or zirconium acid ester and at least one organofunctional polysiloxane in an organic solvent system,
- (2) a binder composition consisting essentially of at least one titanium or zirconium acid ester, at least one titanium or zirconium chelate and at least one organofunctional polysiloxane in a solvent system selected from the group which consists of at least one alcohol, at least one hydrocarbon, a mixture of at least one alcohol and at least one hydrocarbon and mixtures thereof with water, and
- (3) a binder composition consisting essentially of at least one titanium or zirconium chelate and at least one organofunctional polysiloxane in a solvent system selected from the group which consists of water, at least one alcohol, at least one hydrocarbon, and mixtures thereof,
- thereby coating said workpiece with an at least partially inorganic protective coating capable of protecting the chromated or passivated zinc or zinc-alloy coating directly against corrosion;
- and
- (b) drying said protective coating on said workpiece.
A protective coating on a chromated or passivated zinc or zinc alloy coating on a steel workpiece which consists essentially of a titanium acid ester in a binder composition with a polysiloxane, a titanium acid ester and a titanium chelate in a binder system with an organofunctional polysiloxane or a titanium chelate in a binder composition with an organofunctional polysiloxane.
A solution for the dipping of a steel workpiece having a chromated or passivated zinc or zinc alloy coating for applying a protective coating thereto, said solution being a solution of a binder composition in a solvent system selected from the group which consists of:
- (1) a binder composition consisting essentially of at least one titanium or zirconium acid ester and at least one organofunctional polysiloxane in an organic solvent system,
- (2) a binder composition consisting essentially of at least one titanium or zirconium acid ester, at least one titanium or zirconium chelate and at least one organofunctional polysiloxane in a solvent system selected from the group which consists of at least one alcohol, at least one hydrocarbon, a mixture of at least one alcohol and at least one hydrocarbon and mixtures thereof with water, and
- (3) a binder composition consisting essentially of at least one titanium or zirconium chelate and at least one organofunctional polysiloxane in a solvent system selected from the group which consists of water, at least one alcohol, at least one hydrocarbon, and mixtures thereof.
Dependencies are inferred from the claim text.