Patent ID: 6521029
Filing Date: 2003-02-18
Classification: C09D,C23C

Abstract:
A process for pretreating aluminum and alloys of aluminum to improve the corrosion-resistance, and adhesion properties which comprises treating said aluminum and alloys of aluminum with an acidic aqueous solution having a pH ranging from about 2.5 to 4.5 and comprises, per liter of said solution, from about 0.01 to 22 grams of a water soluble trivalent chromium compound, about 0.01 to 12 grams of an alkali metal hexafluorozirconate, about 0.01 to 12 grams of at least one fluoro-compound selected from the group consisting of alkali metal tetrafluoroborates, alkali metal hexafluorosilicates and mixtures thereof, from 0 to 10 grams of at least one water soluble thickener and 0 to 10 grams of at least one water soluble surfactant.