| abstract |
PROBLEM TO BE SOLVED: To provide an aqueous rust preventive surface treatment composition capable of forming a film having high corrosion resistance on the surface of a metal member. The aqueous rust preventive surface treatment composition of the present invention is an aqueous rust preventive surface treatment composition used for forming a film on the surface of a metal member, which comprises a silane coupling agent and a water-soluble titanium compound or A water-soluble transition metal compound containing a water-soluble zirconium compound, a condensed phosphate, and a solvent containing water, wherein the condensed phosphate is a salt of a highly condensed polyphosphoric acid of 4 or more. Contains some highly condensed phosphate. [Selection diagram] None |