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US 5,380,374 AGranted
Conversion coatings for metal surfaces
AssigneeCircle-Prosco, Inc.
InventorCharles E. Tomlinson
Life of this patent
Estimating the term…
Abstract
A conversion coating for aluminum, ferrous and magnesium alloyed materials includes zirconium, fluoride and calcium ions. The coating is preferably at a pH of between about 2.6 and about 3.1, and may optionally include phosphates, polyphosphates, tannin, boron, zinc and aluminum. A sequestering agent to complex dissolved iron, and a crystal deformation agent such as ATMP are also preferably included.
Claims27
An aqueous composition for coating aluminum, ferrous or magnesium alloys, comprising:
- (a) between about 10 ppm and about 5,000 ppm, based on the aqueous composition, of dissolved Group 4 metal ions selected from the group consisting of titanium, zirconium and halfnium;
- (b) between about 80 ppm and about 1300 ppm, based on the aqueous composition, of dissolved Group 2 metal ions selected from the group consisting of magnesium and calcium;
- (c) between about 10 ppm and about 6,000 ppm, based on the aqueous composition, of dissolved fluoride ions;
- and
- (d) water;
- said composition having a pH of between about 2.0 and about 5.0.
3 more elements
A method of treating metal, comprising applying to the metal an aqueous coating composition comprising:
- (a) between about 10 ppm and about 5,000 ppm, based on the aqueous composition, of dissolved metal ions selected from the group consisting of titanium, zirconium and halfnium;
- (b) between about 80 ppm and about 1300 ppm, based on the aqueous composition, of dissolved metal ions selected from the group consisting of magnesium and calcium;
- (c) between about 10 ppm and about 6,000 ppm, based on the aqueous composition, of dissolved fluoride ions;
- and
- (d) water;
- said composition having a pH of between about 2.0 and about 5.0.
3 more elements
Dependencies are inferred from the claim text.