METAL SURFACE TREATMENT LIQUID, SURFACE TREATMENT METHOD FOR METAL BASES, AND METAL BASE OBTAINED BY SURFACE TREATMENT METHOD FOR METAL BASES

摘要

A metal surface treatment liquid for use in forming a composite coating film containing a Bi element and a Group 4 element on a metal base. The metal surface treatment liquid is a fluorine-free aqueous treatment liquid containing (A) a Bi element source, (B) a multimer of at least one Group 4 element selected from the group consisting of Zr, Ti and Hf elements, and (C) one or more aminopolycarboxylic acids or a salt thereof.