POSCO Holdings Inc.
BILAYER COMPOSITION FOR SURFACE TREATMENT OF STEEL PLATE AND SURFACE-TREATED STEEL PLATE USING SAME

Abstract:

Provided is a bilayer composition for surface treatment of a steel plate and a surface-treated steel plate using same. The bilayer composition for surface treatment of a steel plate, comprising an undercoat coating composition including 1 to 12 wt % of a phenoxy resin, 0.001 to 1.0 wt % of colloidal silica, 0.001 to 1.0 wt % of a silane coupling agent, 0.1 to 1.0 wt % of a corrosion inhibitor, 0.001 to 1.0 wt % of a phosphoric acid compound as a long-term corrosion resistance improving agent, and a balance of water; and a topcoat coating composition including 0.1 to 5.0 wt % of an acrylic acid resin, 30 to 50 wt % of colloidal silica, 40 to 60 wt % of alkoxy silane, 5 to 15 wt % of an acrylate-based monomer, 0.01 to 1.00 wt % of an acidity control agent, and a balance of an organic solvent.