CR-FREE COATED STEEL SHEET WITHOUT RESIN COATING, PREPARING METHODS THEREOF AND COATING COMPOSITION THEREFOR

摘要

A chromium-free surface-treated steel plate of resin abbreviation type, a manufacturing method for the same, and chromium-free processing liquid for the same are provided to reduce manufacturing processes and to save manufacturing cost since a resin processing is omitted after a chromium-free processing. A manufacturing method for a chromium-free surface-treated steel plate of resin abbreviation type comprises: a step of coating the chromium-free processing liquid on an electricity zinc-based metal plated steel sheet; and a forming a chromium-free layer by heating the chromium-free processing liquid coated steel sheet at 160~250°C. The electricity zinc-based metal plated steel sheet is an electricity zinc-based metal plated steel sheet in which zinc or Zn-Ni is coated on a cold rolled steel with the plating adhesive amount of 20~30g/m^2. The chromium-free processing liquid includes: a binder resin: 10~50 weight% of one or more types selected from groups consisting of silicate: 3~40 weight%, silane: 0.5~10 weight%, titanium: 0.2~8 weight%, urethane resin and epoxy resin; titanium carbonate: 2~5 weight%; and titanium phosphate: 1~5 weight%.