Metal surface treatment composition, metal surface treatment method, and metal material

A metal surface treatment composition for use in metal surface treatment, containing

• at least one compound selected from the group consisting of a zirconium compound and a titanium compound;
• a fluorine compound;
• and
• an organosiloxane having at least two amino groups in an end terminal thereof, which is a polycondensate of an organosilane composition comprising organosilane, wherein the organosilane has an amino group at an end thereof,
• the Degree of polycondensation of the organosiloxane represented by the following formula (1) is at least 40%,
• the content of compound selected from at least one compound of the group consisting of the zirconium compound and titanium compound in the metal surface treatment composition is from 10 ppm to 10000 ppm with respect to the metal element,
• the content of the organosiloxane in the metal surface treatment composition is from 1 ppm to 2000 ppm with respect to the silicon element,
• the mass ratio of at least one element selected from the group consisting of a zirconium element and a titanium element contained in the zirconium compound and the titanium compound, respectively, to a silicon element contained in the organosiloxane is from 0.5 to 500, and
• the content of free fluorine element in the metal surface treatment composition being from 0.01 ppm to 100 ppm.:
• [Formula 1]
• Degree of polycondensation %=mass of organosiloxane×100/(mass of unreacted organosilane+mass of organosiloxane) Formula (1)
• wherein, the mass of organosiloxane refers to the mass of total of dimers and larger multimers of the organosilane, and does not include the mass of unreacted organosilane.