JPS56113382A - Coating steel article with corrosion suppressing layer - Google Patents

Abstract

PURPOSE:To suppress the corrosion of a steel article with the dissolution of a corrosion suppressor in case where a defect is generated, by forming on the surface of the steel article an under-coat layer containing micro capusles reserving a corrosion suppressor as a core therein, and forming an ordinary coating layer on the under- coat layer. CONSTITUTION:A paint for making an under-coat layer, which is selected according to its application, is mixed with micro capusles reserving therein as a core one or more kinds of corrosion suppressor such as organic oxygen compounds, organic nitrogen compounds, organic sulfur compounds, unsaturated hydrocarbon compound etc. The mixture is applied as an under-coat layer 2 onto the surface of a steel article 1 which is previously cleaned. The steel article 1 is then coated with an upper coat layer 3. Owing to the existence of the wall film of the micro capusle, the corrosion inhibitor does not react with a resin, but keeps its corrosion suppressing effect for a long time. In case where a defect 4 is generated in the layers, the corrosion suppressor is dissolved from the under-coat layer 2 into a corrosive solution at a controlled dissolution speed due to the existence of the wall film. The dissolved agent 5 maintains a corrosion suppressing film 7 on the surface of the steel article 1 for a long time.