| 摘要 |
A first characteristic of the invention is present in forming a chromate film on the surface of a zinc or a zinc alloy plated steel sheet, and a resin composition film at a coating amount of 0.3 to 5.0 g/m<2> on said chromate film, where an organic solvent soluble epoxy resin is composed with hydrophobic silica, said epoxy resin having a glass transition temperature of 293 to 342 DEG K and said hydrophobic silica being at composition rate of 80 : 20 to 50 : 50 of weight ratio of epoxy resin : hydrophobic resin. A second characteristic of the invention is present in froming a chromate film on the surface of a zinc or zinc alloy plated steel sheet, and a resin composition film at a coating amount of 0.3 to 5.0 g/m<2> on said chromate film, where an organic solvent soluble epoxy resin having glass transition temperature of 293 to 342 DEG K is composed with hydrophobic silica and sparingly water soluble Cr compound at 80 : 20 to 50 : 50 of weight ratio of epoxy resin : (hydrophobic silica + sparingly water soluble Cr compound), and at 37 : 3 to 20 : 20 of weight ratio of hydrophobic silica : sparingly water soluble Cr compound. |
