Patent ID: 8535456

Claim:
A chemical conversion treatment solution comprising: an acidic aqueous solution of pH 3 to 5 containing 50 to 500 ppm by weight of zirconium fluoride complex in terms of Zr, 5 to 50 ppm by weight of free fluorine, and 5 to 30% by weight in relation to Zr of polyethyleneimine, wherein the polyethyleneimine has a weight average molecular weight of 300 to 10,000 and the polyethyleneimine has a primary amino group, a secondary amino group, and a tertiary amino group and a molar ratio of the primary amino group in relation to total content of the primary, secondary and tertiary amino groups is at least 30% and a molar ratio of the tertiary amino group in relation to the total content of the primary, secondary and tertiary amino groups is at least 15%.