Chromate treatment bath composition and process for application to metals
AssigneeHenkel Corporation
InventorsTakashi Oue, Kensuke Mizuno
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Abstract
A chromate treatment bath composition, afforded by the introduction, into an aqueous solution containing hexavalent Cr ions and trivalent Cr ions, of a nonionic-anionic composite surfactant that has an anionic moiety and a nonionic moiety composed of a polyethylene glycol group or a group consiting of an ethylene oxide addition polymer, provides metal surfaces onto which a layer of the composition containing 5 to 150 mg/m.sup.2 of total chromium is dried with a chromate film that has an excellent alkali resistance and water resistance, a high chromium fixing ratio, an excellent corrosion resistance, and an excellent paint film adherence.
Claims20
An aqueous liquid chromate treatment bath composition suitable for application to metals as a dry-in-place treatment, said composition comprising water and:
- (A) an amount of dissolved hexavalent chromium ions;
- (B) an amount of dissolved trivalent chromium ions;
- and
- (C) an amount of a dissolved nonionic-anionic composite surfactant component selected from the group of surfactant molecules each of which comprises:
- (C.1) a hydrophobic part;
- and
- (C.2) a hydrophilic part that has a composite structure that contains both (C.2.1) a nonionic moiety conforming to the general formula:
- --(C.sub.2 H.sub.4 O).sub.n --,
- where n is a positive integer with a value of at least two and (C.2.2) an anionic moiety.
Dependencies are inferred from the claim text.