Sn-plated steel sheet and method for manufacturing Sn-plated steel sheet

A Sn-plated steel sheet, comprising:

• a base plated steel sheet having a steel sheet, and a Sn-plated layer on at least one surface of the steel sheet;
• and
• a film layer which contains a zirconium oxide and a tin oxide and is positioned on the base plated steel sheet, where the Sn-plated layer and the film layer are formed in this order on at least one surface of the steel sheet,
• wherein an adhesion amount of Sn per surface is 0.1 g/m2 or more and 15 g/m2 or less,
• the adhesion amount of Sn per surface is a sum of an amount of Sn, which is present in the Sn-plated layer and not diffused into the film layer, and an amount of the tin oxide present in the film layer in terms of an amount of metal Sn,
• an amount of the zirconium oxide in the film layer is in a range of 1 mg/m2 or more and 30 mg/m2 or less in terms of an amount of metal Zr,
• a peak position of a binding energy of Sn3d5/2 of the tin oxide by X-ray photoelectron spectroscopy in the film layer is within a range of 1.4 eV or more and less than 1.6 eV from a peak position of a binding energy of metal Sn, and
• a quantity of electricity required for reduction of the tin oxide is in a range of more than 5.0 mC/cm2 and 20 mC/cm2 or less,
• wherein the quantity of electricity required for reduction of the tin oxide is measured by:
• providing a 0.001 mol/L aqueous solution of hydrobromic acid from which dissolved oxygen has been removed by bubbling of nitrogen gas;
• subjecting the Sn-plated steel sheet to cathodic electrolysis in said aqueous solution, at a constant current of 0.06 mA/cm2, and
• calculating the quantity of electricity required for the reduction of the tin oxide from the product of the time and current values required for reducing and removing the tin oxide.