Chemical conversion treatment agent for surface treatment of metal substrate, and surface treatment method of metal substrate using same

A chemical conversion treatment agent for surface treatment of a metal substrate, comprising:

• at least one metal element selected from the group consisting of zirconium, titanium, and hafnium;
• fluorine element;
• and
• a co-condensate of a silane coupling agent (A) and a silane coupling agent (B), wherein the silane coupling agent (A) is a silane coupling agent having a tri- or di-alkoxysilane group and an amino group, and
• the silane coupling agent (B) is a silane coupling agent represented of formula (1):
• wherein
• R is selected from the group consisting of alkylene groups having 1 to 5 carbon atoms, alkyleneoxy groups having 1 to 5 carbon atoms, and an oxygen atom,
• Z is selected from the group consisting of cyclohexyl groups each optionally having at least one of an epoxy group and an amino group as a substituent and aromatic ring groups each optionally having at least one of a vinyl group, an epoxy group, and an amino group as a substituent,
• a, b, and c are each an integer of 0 to 3, provided that a sum of a, b, and c is 3, and a sum of a and b is 2 to 3, and
• x is an integer of 1 to 3.