SURFACE TREATMENT COMPOSITION FOR TERNARY HOT DIP GALVANIZED STEEL SHEET, SURFACE-TREATED TERNARY HOT DIP GALVANIZED STEEL SHEET USING SAME, AND PREPARATION METHOD THEREOF

摘要

The present invention provides a surface treatment composition capable of conferring corrosive resistance, blackening resistance, alkali resistance, and an intrinsic surface color property on a ternary hot dip galvanized steel sheet. The present invention provides a surface-treated composition comprising: 70 to 90 weight% of a resin mixture comprising a high-molecular weight polysilicon-modified polyurethane main resin, a low-molecular weight polysilicon-modified polyurethane auxiliary resin, and an acryl-urethane auxiliary resin; 5 to 25 weight% of a melamine-based curing agent; 0.5 to 10 weight% of an inorganic additive; 0.5 to 10 weight% of a silane coupling agent; 0.1 to 2 weight% of an adhesion promoter; 0.1 to 2 weight% of a coloring pigment; and 0.1 to 1 weight% of a pigment stabilizer, on the basis of 100 weight% of the solid content of the composition.