Aqueous zinc solution resistant to precipitation
AssigneeOlin Corporation
InventorArvind Parthasarathi
Life of this patent
Estimating the term…
Abstract
There is disclosed an aqueous chemical solution that consists essentially of zinc ions, a source of hydroxides, and silicon ions. The ratio of silicon to zinc (Si:Zn) is, by weight from about 1:5 to about 1:250. Within the ratio range, the silicon ions inhibit precipitation of zinc from the chemical solution. This is particularly useful when the chemical solution is an electrolyte for the deposition of zinc or a zinc containing compound onto a metallic structure where a critical zinc content must be maintained to impart adequate adhesion of a coated substrate to a polymer adhesive.
Claims7
A method for preparing an electrolyte for the deposition of a zinc containing anti-tarnish coating on a metallic substrate by inhibiting the precipitation of zinc from said electrolyte comprising the steps of:
- a) supplying an aqueous medium having a pH in excess of 7;
- b) dissolving in said aqueous medium silicon, from a water soluble silicon source, in an amount that provides a silicon ion content effective to inhibit precipitation of zinc from said electrolyte;
- and
- c) subsequent to said step (b) dissolving from a minimum of 0.8 gram per liter to about 30 grams per liter of zinc ions.
Dependencies are inferred from the claim text.