IMPROVED CHROME FREE RESIN COMPOSITION FOR GOOD SUSTAINABILITY AT HIGH HUMIDITY OR AT HIGH TEMPERATURE HIGH HUMIDITY ENVIRONMENT BY USING THE RESIN COMPOSITION AND THE SURFACE TREATING METHOD

摘要

PURPOSE: Chromium-free resin composition with improved heat resistance and high-temperature/high-humidity resistances, a surface-treated steel sheet using the chromium-free resin composition and a manufacturing method thereof are provided to improve the alkali and corrosion resistances of a steel sheet by employing the resin composition containing no chromium. CONSTITUTION: A resin composition for surface treatment of a steel sheet comprises urethane resin containing fluorine-based resin 10~90 weight%, Ti or Zr organic oxide 1~20 weight%, a phosphate compound 0.1~10 weight%, water repellent 0.5~20 weight%, and a solvent. The water repellent is selected from the group consisting of potassium zirconium carbonate, ammonium zirconyl carbonate and their compound.