Pretreatment of tinplate prior to the coating thereof with lacquer

US9909227B2 · kind B2 · utility

Assignee

• Henkel AG & Co. KGaA · DE

Inventors

• Uta Sundermeier · Leichlingen, DE
• Michael Wolpers · Erkrath, DE
• Marcel Roth · Goldkronach, DE
• Jurgen Stodt · Neuss, DE

Key dates

• Filing date: Mar 13, 2013
• Grant date: Mar 6, 2018
• Expiry date: Sep 6, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25D11/34
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

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.