Pretreatment for aluminum and aluminum alloys
First Claim
1. 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.
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Accused Products
Abstract
Pretreated aluminum and aluminum alloys and the process for pretreating said aluminum substrates to improve its corrosion-resistance, and adhesion properties which comprises pretreating said aluminums with an effective amount of an acidic aqueous solution having a pH ranging from about 2.5 to 4.5 and comprises effective amounts of a trivalent chromium compound, alkali metal hexafluorozirconates, at least one alkali metal fluoro-compound, and small but effective amounts of water soluble thickeners and/or surfactants.
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Citations
20 Claims
- 1. 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.
- 6. 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 aqueous solution having a pH ranging from about 3.7 to 4.0 and comprises per liter of solution from about 5.0 to 7.0 grams of a water soluble trivalent chromium salt, about 6.0 to 8.0 grams of an alkali metal hexafluorozirconate, and about 0.01 to 1.2 grams of at least one fluoro-compound selected from the group consisting of alkali metal tetrafluoroborates, alkali metal hexafluorosilicates and mixtures thereof.
- 11. Pretreated aluminum and alloys of aluminum having improved corrosion-resistance, and adhesion properties comprising said aluminum and alloys of aluminum treated with a coating amount of an acidic aqueous solution having a pH ranging from about 2.5 to 4.5 and comprising per liter of said solution about 0.01 to 22 grams of a water-soluble trivalent chromium compound, from 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 an alkali metal tetrafluoroborate, an alkali metal hexafluorosilicate and mixtures thereof, from 0 to 10 grams of at least one water soluble thickener and from 0 to 10 grams of at least one water soluble surfactant.
- 16. Pretreated aluminums and alloys of aluminum having improved corrosion-resistance and adhesion properties comprising said aluminum and alloys of aluminum treated with a coating amount of an acidic aqueous solution having a pH ranging from about 3.7 to 4.0, and containing per liter of said solution from about 0.01 to 10 grams of a water soluble trivalent chromium salt, about 0.01 to 8 grams of an alkali metal hexafluorozirconate, about 0.01 to 1.2 grams of at least one fluoro-compound selected from the group consisting of an alkali metal tetrafluoroborate, an alkali metal hexafluorosilicate and mixtures thereof, from 0 to 10 grams of at least one water soluble thickener and from 0 to 10 grams of at least one water soluble surfactant.
Specification