Back to results
US 2010/0132843 A1Published application
Trivalent Chromium-Containing Composition for Use in Corrosion Resistant Coatings on Metal Surfaces
AssigneeHenkel AG & Co. KGaA
InventorKirk Kramer
Life of this patent
Estimating the term…
Abstract
A low sludge trivalent chromium based conversion coating bath is provided which forms corrosion resistant coatings on aluminum and aluminum alloys by immersion in aqueous solutions containing trivalent chromium ions and fluorometallate ions followed by optional rinsing. Trivalent chromium coated aluminum also serves as an effective base for paint primers.
Claims19
A composition for coating a metal surface, said composition comprising water and:
- (A) a component of fluorometallate anions, each of said anions consisting of:
- (i) at least four fluorine atoms;
- and
- (ii) at least one atom of an element selected from the group consisting of titanium, zirconium, hafnium, silicon, aluminum, and boron, and, optionally, one or both of
- (iii) at least one ionizable hydrogen atom;
- and
- (iv) at least one oxygen atom;
- (B) a component of water soluble chromium fluoride;
- said composition being substantially free of hexavalent chromium and storage stable at ambient temperature for at least 2 weeks.
6 more elements
A storage stable composition made by mixing together a first mass of water and at least the following components:
- (A) a second mass of a water-soluble source of fluorometallate anions to provide in the composition from about 1 to about 100 g/kg of the fluorometallate anion, each of said anions consisting of:
- (i) at least four fluorine atoms;
- and
- (ii) at least one atom of an element selected from the group consisting of titanium, zirconium, hafnium, silicon, aluminum, and boron, and, optionally, one or both of
- (iii) at least one ionizable hydrogen atom;
- and
- (iv) at least one oxygen atom;
- (B) a third mass in an amount of 23 g/l to about 100 g/l of a water soluble source of trivalent chromium cations;
- (C) an optional fourth mass of water-soluble source of fluorine anions;
- (D) an optional fifth mass of a component of surfactant and/or water soluble thickener;
- said composition being free of water-soluble organic corrosion inhibitor and water-soluble organic stabilizing agents and storage stable at ambient temperature for at least 2 weeks.
8 more elements
Dependencies are inferred from the claim text.