| Patent application number | Description | Published |
|---|
| 20130192995 | PRETREATMENT OF TINPLATE PRIOR TO THE COATING THEREOF WITH LACQUER - 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 M | 08-01-2013 |
| 20130299379 | MULTISTAGE PRETREATMENT OF TINPLATE PRIOR TO THE COATING THEREOF WITH LACQUER - 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. | 11-14-2013 |
| 20140360630 | PRETREATING ZINC SURFACES PRIOR TO A PASSIVATING PROCESS - 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 α, β, or γ position with respect to the acid group and/or the water-soluble salts thereof. | 12-11-2014 |
