摘要 |
An agent for treating metal surfaces which comprises an aqueous medium and, incorporated therein, (A) a cationic urethane resin which is water-soluble or in an aqueous emulsion form, (B) a cationic polycondensation product obtained from a phenol compound and an aldehyde, and (C) a zirconium compound and/or titanium compound. A coating film formed from the treating agent imparts excellent corrosion resistance and alkali resistance to a metallic material. When the proportion of the urethane resin (A) is equal to or higher than that of the polycondensation product (B), yellowing resistance can be also imparted. By incorporating a metal compound (D) containing a specific metal, excellent blacking resistance also can be imparted. Furthermore, by incorporating an acid ingredient (E) and a vanadium compound (F), a further improvement in performances can be attained.
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