Use of additive in aqueous cure of autodeposited coatings
AssigneeAmchem Products, Inc.
InventorBashir M. Ahmed
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Abstract
Curing of autodeposited coatings by treatment with water or steam including a solute.
Claims20
A process for curing an uncured autodeposited coating comprising contacting a metallic surface with an autodepositing composition having resin solids dispersed in the aqueous phase of said composition to form on said surface an uncured autodeposited coating in the form of resin solids adhered thereto and subjecting said uncured autodeposited coating to steam or to water having a temperatur of at least about 70.degree. C. and having solute dissolved therein for a period of time sufficient to cure said coating, said solute being present in an amount sufficient to improve the adhesive properties of said cured coating and being a surfactant, a strong acid, a strong base, a weak acid, a weak base, a salt of such acid or base, a metal oxide, a transitional metal complex or a mixture of two or more of the foregoing compounds.
In a process wherein a water film is sandwiched between an overlying uncured autodeposited coating and an underlying coated metallic surface and in which said uncured coating is cured by contacting it with an aqueous curing medium for a sufficient period of time to cure said coating, the improvement comprising dissipating said water film in the presence of said aqueous curing medium and during the curing of said coating.
In a process wherein a water film is sandwiched beteen an overlying substrate and in which said uncured coating is cured by contacting it with an aqueous curing medium for a sufficient period of time to cure said coating, the improvement comprising dissipating said water film by contacting the coating with an aqueous solution of solute, said solute being a surfactant, a strong acid, a strong base, a weak acid, a weak base, a salt of such acid or base, a metal oxide, a transitional metal complex or a mixture of two or more of the foregoing compounds.
Dependencies are inferred from the claim text.