CHROME-FREE COATING COMPOSITIONS FOR STEEL SHEET INCLUDING CARBON NANOTUBE, METHODS FOR SURFACE TREATED STEEL SHEET AND GALVANIZED STEEL SHEETS USING THE SAME

摘要

A coating composition for steel sheet including carbon nanotube, a surface treatment method for steel sheet and a steel sheet treated by the same are provided to coat a steel sheet using the chromium-free composition for metal surface treatment containing carbon nanotube, thereby obtaining excellent property even when curing at low temperature. A steel sheet with superior electric conductivity comprises main resin of water soluble organic resin 40~60wt%, inorganic metal sol 20~40wt%, carbon nanotube paste including carbon nanotube 2~5wt%, metal oxide phosphate anti-corrosion agent 2~5wt%, organometallic complex compound 5~15wt%, and cross-linking agent 3~7wt%. The water soluble organic resin is selected from the group consisting of water-dispersible urethane resin having carboxyl group or hydroxyl group and acrylic resin having carboxyl group or hydroxyl group.