SURFACE TREATED STEEL SHEET FOR FUEL VESSEL AND COATING MATERIAL COMPOSITION THEREFOR

摘要

PROBLEM TO BE SOLVED: To produce a surface treated steel sheet using a Zn or Zn alloy plated steel sheet as a base stock, being excellent in corrosion resistance against degraded gasoline containing organic acids, provided with advanced weldability, having excellent formability and suitable for a fuel tank for automobiles. SOLUTION: A thermosetting resin layer containing one or more kinds of metallic pigments A selected from Ni, Al and an Ni-Al alloy and one or more kinds of pigments B selected from iron phosphide and ferrosilicon in a modified epoxide resin is applied by 3-10 g/m2 coating weight on the chemically converted Zn or Zn alloy plated steel sheet. The total quantity of the pigment in the resin layer is preferably controlled to 10-70 wt.%, the ratio of pigment A/ pigment B is preferably controlled to 90/10 to 30/70 and the average particle diameter of each pigment is preferably controlled to 0.5-15μm.