| abstract |
The present invention relates to a composition for surface treatment of a two-layer steel sheet and a steel sheet surface-treated using the same, and more specifically, 1 to 12% by weight of phenoxy resin and 0.001 to 1.0% by weight of colloidal silica based on the total weight of the coating composition for primer. , Silane coupling agent 0.001 to 1.0% by weight, corrosion inhibitor 0.1 to 1.0% by weight, long-term corrosion resistance improver coating composition for a primer containing 0.001 to 1.0% by weight of the phosphoric acid compound and the balance of water; And 0.1 to 5.0% by weight of acrylic acid resin, 30 to 50% by weight of colloidal silica, 40 to 60% by weight of alkoxy silane, 5 to 15% by weight of acrylate monomer, and 0.01 to 1.00% of acidity adjusting agent based on the total weight of the coating composition for top coat %, and a composition for surface treatment of a two-layer steel sheet comprising a coating composition for a top coat containing an organic solvent in the balance, a surface treatment method of a steel sheet for improving corrosion resistance using the same, and a surface-treated steel sheet. |