Coated metal fastener and method for making same
AssigneeIllinois Tool Works Inc.
InventorsGeronimo E. Lat, William L. Gabriel
Life of this patent
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Abstract
A metal fastener, suitable for use in connection with wood construction and coated with a polymeric residue produced by removing water from an aqueous dispersion of a film-forming, thermoplastic, predominantly aliphatic polyurethane resin, so as to thereby reduce penetration force, increase withdrawal force, and protect against corrosion, is disclosed. Before the polyurethane coating is applied, a zinc layer is applied so as to coat the fastener, and a chromate conversion layer is applied so as to coat the zinc layer.
Claims24
A method for producing a metal fastener, which comprises the steps of:
- applying a zinc coating over substantially the entire metal surface of said metal fastener;
- applying a chromate conversion coating upon said zinc coating;
- applying an aqueous dispersion coating containing a film-forming, thermoplastic, predominantly aliphatic polyurethane resin upon said chromate conversion coating;
- and
- heating said fastener, having said zinc, chromate conversion, and aqueous dispersion coatings applied thereto, to an elevated temperature greater than room temperature so as to remove water from said applied aqueous dispersion coating and thereby form a protective film upon said fastener from said predominantly aliphatic polyurethane resin residue which also covers said zinc and chromate conversion coatings.
A method for producing a metal fastener suitable for use in connection with wood construction, comprising the steps of:
- applying a zinc layer over substantially the entire metal surface of said metal fastener;
- applying a chromate conversion layer upon said zinc layer;
- and
- applying a thermoplastic, predominantly aliphatic polyurethane coating over said chromate conversion layer.
A method for producing a metal fastener, comprising the steps of:
- applying a protective coating over substantially the entire metal surface of said metal fastener, said protective coating comprising at least one of the components chosen from the group of zinc phosphate, iron phosphate, tin, zinc, aluminum, or stainless steel;
- and
- applying an aqueous dispersion coating containing a film-forming, thermoplastic, predominantly aliphatic polyurethane resin upon said protective coating;
- and
- heating said fastener, having said protective and aqueous dispersion coatings thereon, to an elevated temperature greater than room temperature so as to remove water from said applied aqueous dispersion coating and thereby form a protective film upon said fastener from said predominantly aliphatic polyurethane resin residue which also covers said protective coating.
Dependencies are inferred from the claim text.