| 摘要 |
PCT No. PCT/US91/00965 Sec. 371 Date Aug. 20, 1993 Sec. 102(e) Date Aug. 20, 1993 PCT Filed Feb. 13, 1991 PCT Pub. No. WO91/13186 PCT Pub. Date Sep. 5, 1991.The paint adhesion and corrosion resistance of surfaces of aluminum and its alloys, particularly when using a paint based on poly{vinyl chloride}, is improved by using a conversion coating solution having a pH in the range from 1.0 to 3.0 and consisting essentially of water and: (A) an amount of phosphate ions that is stoichiometrically equivalent to at least 5.0 g/L of phosphoric acid; (B) at least 1.0 g/L of hexavalent chromium; (C) at least 0.1 g/L of fluoride ions; and (D) a complex fluoride ion component selected from the group consisting of: (i) at least 4.0 g/L of fluosilicate ions, (ii) at least 0.5 g/L of fluoborate ions, (iii) at least 2.0 g/L of fluozirconate ions, and (iv) at least 2.0 g/L of fluotitanate ions.
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