Abstract: 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 ?, ?, or ? position with respect to the acid group and/or the water-soluble salts thereof.

Abstract: The object of the underlying invention consists of an acidic aqueous metal pretreatment solution that comprises amino-functional organosilanes and organophosphorus acids. These types of metal pretreatment solutions effectively reduce temporary corrosion when applied to metal surfaces and in addition confer good adhesion properties for subsequently coated organic lacquers. The invention consequently also encompasses a process for the treatment of metal substrates, especially selected from zinc and zinc-coated steel substrates, wherein metal pretreatment solutions of this invention are applied.

Abstract: The invention is directed to an acidic aqueous metal pretreatment solution that comprises amino-functional organosilanes, complex anions of the elements Zr, Ti, Hf and/or Si as well as oxyacids of phosphorus; a process for the treatment of metal substrates, especially selected from zinc and zinc-coated steel substrates, wherein metal pretreatment solutions of this invention are applied to reduce corrosion when applied to metal surfaces and in addition confer good adhesion properties for subsequently coated organic lacquers.

Abstract: The invention relates to a two-stage method for the anti-corrosive pretreatment of tinplate, in which an anti-corrosive primer coating is applied in a first step, in which the tinplate is anodically polarized in an electrolyte containing at least one inert water-soluble salt and is then in a second step, brought in contact with an acidic aqueous composition containing water-soluble inorganic compounds of the elements Zr, Ti, Hf, and/or Si.

Abstract: The invention relates to a method for the anti-corrosive pretreatment of tinplate, in which an anti-corrosive primer coating is applied in a single step, said primer coating effectively preventing the shiny metal surface of the pretreated tinplate from turning black when the pretreated tinplate of the invention that is provided with a topcoat is in contact with liquids releasing or containing sulfur compounds and with food containing protein. In the disclosed method, the tinplate is anodically polarized in an electrolyte containing silicates of formula M2O.nSiO2, where M is an alkali metal ion or quaternary ammonium ion and n is a natural number between 0.8 and 7. Tinplate pretreated according to the invention can be used in particular for the production of food-safe packaging such as beverage cans or tin cans.

Abstract: The present invention relates to an alkaline aqueous composition on the basis of water glass and organosilanes with non-hydrolysable substituents which have a primary amino group in the substituents, for providing corrosion-protected coatings on metal surfaces which convey good reshaping properties in metal processing. For the desired functionality, the compositions according to the invention contain the organosilane and the water glass in a predetermined ration. The invention further relates to a method for pre-treating metal surfaces using the alkaline aqueous compositions, which method provides excellent results with regard to corrosion protection, varnish adhesion and reshapability, particularly on aluminum and on steel strips provided with aluminum alloy metal coatings.

Abstract: The object of the underlying invention consists of an acidic aqueous metal pretreatment solution that comprises amino-functional organosilanes and organophosphorus acids. These types of metal pretreatment solutions effectively reduce temporary corrosion when applied to metal surfaces and in addition confer good adhesion properties for subsequently coated organic lacquers. The invention consequently also encompasses a process for the treatment of metal substrates, especially selected from zinc and zinc-coated steel substrates, wherein metal pretreatment solutions of this invention are applied.

Abstract: The invention is directed to an acidic aqueous metal pretreatment solution that comprises amino-functional organosilanes, complex anions of the elements Zr, Ti, Hf and/or Si as well as oxyacids of phosphorus; a process for the treatment of metal substrates, especially selected from zinc and zinc-coated steel substrates, wherein metal pretreatment solutions of this invention are applied to reduce corrosion when applied to metal surfaces and in addition confer good adhesion properties for subsequently coated organic lacquers.

Abstract: 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.

Abstract: The present invention relates to an alkaline aqueous composition on the basis of water glass and organosilanes with non-hydrolysable substituents which have a primary amino group in the substituents, for providing corrosion-protected coatings on metal surfaces which convey good reshaping properties in metal processing. For the desired functionality, the compositions according to the invention contain the organosilane and the water glass in a predetermined ration. The invention further relates to a method for pre-treating metal surfaces using the alkaline aqueous compositions, which method provides excellent results with regard to corrosion protection, varnish adhesion and reshapability, particularly on aluminum and on steel strips provided with aluminum alloy metal coatings.

Abstract: 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 ?, ?, or ? position with respect to the acid group and/or the water-soluble salts thereof.

Abstract: The invention relates to a two-stage method for the anti-corrosive pretreatment of tinplate, in which an anti-corrosive primer coating is already applied in a first step, said primer coating effectively preventing the shiny metal surface of the pretreated tinplate from turning black when the pretreated tinplate of the invention that is provided with a coating lacquer is in contact with liquids containing or releasing sulfur compounds and with food containing protein. In the disclosed method, the tinplate is anodically polarized in an electrolyte containing at least one inert water-soluble salt and is then brought in contact with an acidic aqueous composition containing water-soluble inorganic compounds of the elements Zr, Ti, Hf, and/or Si. Tinplate pretreated according to the invention can be used in particular for the production of food-safe packaging such as beverage cans or tin cans.

Abstract: The invention relates to a method for a preliminary metallizing treatment of galvanized or zinc alloy-coated steel surfaces or joined metallic parts that at least partly have zinc surfaces, in a surface treatment encompassing several process steps. In the disclosed method, metallic coats of especially a maximum of 100 mg/m2 of molybdenum, tungsten, cobalt, nickel, lead, tin, and/or preferably iron are produced on the treated zinc surfaces. Another embodiment of the invention relates to an uncoated or subsequently coated metallic part which has been subjected to the disclosed preliminary metallizing treatment as well as the use of such a part for making bodies during the production of automobiles, building ships, in the construction industry, and for manufacturing white products.

Abstract: The invention relates to a method for a preliminary metallizing treatment of galvanized or zinc alloy-coated steel surfaces or joined metallic parts that at least partly have zinc surfaces, in a surface treatment encompassing several process steps. In the disclosed method, metallic coats of especially a maximum of 100 mg/m2 of molybdenum, tungsten, cobalt, nickel, lead, tin, and/or preferably iron are produced on the treated zinc surfaces. Another embodiment of the invention relates to an uncoated or subsequently coated metallic part which has been subjected to the disclosed preliminary metallizing treatment as well as the use of such a part for making bodies during the production of automobiles, building ships, in the construction industry, and for manufacturing white products.