Zinciferous plated steel sheet excellent in press-formability and corrosion resistance

In a zinciferous plated steel sheet excellent in press-formability and corrosion resistance, which comprises:

• a steel sheet;
• a zinciferous plating layer formed on at least one surface of said steel sheet;
• a chromate film formed on said zinciferous plating layer, said chromate film having a weight within a range of from 5 to 200 mg/m.sup.2 as converted into metallic chromium per surface of said steel sheet;
• and
• a resin film formed on said chromate film by applying a resin onto said chromate film and then curing same, said resin film having a thickness within a range of from 0.3 to 3.0 .mu.m;
• the improvement wherein:
• said resin film comprises a solvent-base thermosetting resin, a solid internal lubricant and a rust-preventive pigment;
• said solvent-base thermosetting resin comprises:
• (A) urethane prepolymer containing a hydroxyl group and having the following chemical composition:
• (a) at least one polyol selected from the group consisting of polyether polyol, polyester polyol and polyether-polyester polyol;
• (b) an isocyanate compound, and
• (c) dihydric alcohol, and
• (B) at least one of a block polyisocyanate compound and an amino resin as a curing agent;
• said solid internal lubricant comprises a polyethylene resin, and the content ratio of said solid internal lubricant is within a range of from 1 to 30 weight parts relative to 100 weight parts of a solid component in said solvent-base thermosetting resin;
• and
• said rust-preventive pigment comprises at least one of a chromate compound or silica, and the content ratio of said rust-preventive pigment is within a range of from 3 to 30 weight parts relative to 100 weight parts of said solid component in said solvent-base thermosetting resin.