RUST CONVERTER, COMPOSITION FOR PRODUCING SAME, AND PRODUCTION METHOD

摘要

A rust converter includes a tanning extract, oxalic acid, a source of silver, and water. The source of silver consists of silver nitrate, and the rust converter additionally contains oxyethylene diphosphonic acid (I) having the following component ratio by mass%: tanning extract: 6.80-12.70; oxalic acid: 3.80-7.72; silver nitrate: 0.01-0.10; oxyethylene diphosphonic acid (I): 0.15-0.67; water or water with alcohol: the remainder.