Composition and process for treating metal

Abstract

A chemically and thermally stable chromate free aqueous liquid treatment for metals, especially aluminum, that imparts corrosion resistance as good as that from conventional chromate containing treatments, contains water and: (A) a component selected from the group consisting of H.sub.2 TiF.sub.6, H.sub.2 ZrF.sub.6, H.sub.2 HfF.sub.6, H.sub.2 SiF.sub.6, H.sub.2 GeF.sub.6, H.sub.2 SnF.sub.6, HBF.sub.4, and mixtures thereof; and (B) a component selected from the group consisting of water soluble organic carboxylic acids that contain at least two hydroxyl groups, exclusive of the hydroxyl groups that are part of any carboxyl groups, per carboxyl group in each acid molecule, the water soluble salts of such acids, and mixtures of any two or more of these acids and salts; and, optionally, one or more of the following: (C) a component selected from the group consisting of Ti, Zr, Hf, Al, Si, Ge, Sn, and B, the oxides, hydroxides, and carbonates of Ti, Zr, Hf, Al, Si, Ge, Sn, and B, and mixtures of any two or more of these elements, oxides, hydroxides, and carbonates; (D) a component selected from the group consisting of water soluble and water dispersible polymers and copolymers of one or more x-(N--R.sup.1 --N--R.sup.2 -aminomethyl)-4-hydroxy-styrenes, where x=2, 4, 5, or 6, R.sup.1 represents an alkyl group containing from 1 to 4 carbon atoms, and R.sup.2 represents a substituent group conforming to the general formula H(CHOH).sub.n CH.sub.2 -, where n is an integer from 1 to 7; (E) a pH adjusting component selected from the group consisting of inorganic acids and inorganic alkaline materials that do not contain fluorine; (F) a component selected from the group consisting of inorganic acids that contain fluorine but do not contain any of the elements Ti, Zr, Hf, Al, Si, Ge, Sn, and B; and (G) a foam reducing amount of an antifoam agent component.

Dependencies are inferred from the claim text.