Coating methods using silver nanoparticles

Abstract

Methods for coating wires to apply a silver cladding are disclosed herein. Silver nanoparticles are dispersed in a low surface tension solvent to form a coating solution. A wire is drawn through the coating solution to form a coating layer of silver nanoparticles on the wire. The coating layer is then annealed to form the wire with a silver cladding thereon.

1 . A process for forming a cladding on an object, comprising:
 dissolving or dispersing silver nanoparticles in a low surface tension solvent to form a liquid silver nanoparticle composition having a surface tension of from about 22 mN/m to less than 32 mN/m;   drawing an object selected from the group consisting of a wire, a fiber and a filament through the silver nanoparticle composition to form a coating on the object;   annealing the coating to form a layer of silver cladding on the object; and   applying an overcoat layer over the layer of silver cladding.   
     
     
         2 . The process of  claim 1 , wherein the silver cladding has a thickness of from about 10 nm to about 30 micrometers. 
     
     
         3 . The process of  claim 2 , wherein the wire is a bare or insulated conductor having a solid, stranded, or twisted construction designed to carry current in an electrical circuit. 
     
     
         4 . The process of  claim 2 , wherein the wire is plastic or metal. 
     
     
         5 . The process of  claim 4 , wherein the metal wire is selected from the group consisting of copper, aluminum, tungsten and silicon. 
     
     
         6 . The process of  claim 4 , wherein the plastic wire is selected from the group consisting of polyester, polyimide, polyamide, polycarbonate, polyacrylate, and polyethylene. 
     
     
         7 . A process for forming a cladding on an object, comprising:
 dissolving or dispersing silver nanoparticles in a low surface tension solvent to form a liquid silver nanoparticle composition having a surface tension of from about 22 mN/m to less than 32 mN/m;   drawing an object through the silver nanoparticle composition to form a coating on the object;   annealing the coating to form a layer of silver cladding on the object; and   applying an overcoat layer over the layer of silver cladding.   
     
     
         8 . The process of  claim 7 , wherein the overcoat layer is a crosslinked polysiloxane, a crosslinked poly (silsesquioxane), or a crosslinked layer comprising poly(vinylphenol) and a melamine-formaldehyde resin. 
     
     
         9 . The process of  claim 8 , wherein the object is selected from the group consisting of a wire, a fiber and a filament. 
     
     
         10 . The process of  claim 9 , wherein the wire is a bare or insulated conductor having a solid, stranded, or twisted construction designed to carry current in an electrical circuit. 
     
     
         11 . The process of  claim 9 , wherein the wire is plastic or metal. 
     
     
         12 . The process of  claim 11 , wherein the metal wire is selected from the group consisting of copper, aluminum, tungsten and silicon. 
     
     
         13 . The process of  claim 11 , wherein the plastic wire is selected from the group consisting of polyester, polyimide, polyamide, polycarbonate, polyacrylate, and polyethylene. 
     
     
         14 . A process for forming a cladding on an object, comprising:
 dissolving or dispersing silver nanoparticles in a low surface tension solvent to form a liquid silver nanoparticle composition having a surface tension of from about 22 mN/m to less than 32 mN/m;   drawing an object through the silver nanoparticle composition to form a coating on the object; and   annealing the coating to form a layer of silver cladding on the object, wherein the layer of silver cladding has a thickness of from about 10 nanometers to about 50 micrometers.   
     
     
         15 . The process of  claim 14 , wherein the low surface tension solvent is selected from the group consisting of decalin, cyclohexane, dodecane, tetradecane, hexadecane, hexadecane, bicyclohexane, and an isoparaffinic hydrocarbon. 
     
     
       16. The process of  claim 15 , wherein the silver nanoparticle composition contains from about 5 wt % to about 40 wt % of the silver nanoparticles. 
     
     
         17 . A process for forming a cladding on an object, comprising:
 dissolving or dispersing silver nanoparticles in a low surface tension solvent to form a liquid silver nanoparticle composition having a surface tension of from about 22 mN/m to less than 32 mN/m;   drawing an object through the silver nanoparticle composition to form a coating on the object; and   annealing the coating to form a layer of silver cladding on the object, wherein the annealing step occurs at a temperature of from about 100° C. to about 140° C.   
     
     
         18 . The process of  claim 17 , wherein the annealing step occurs for about 5 minutes to about 35 minutes. 
     
     
         19 . The process of  claim 17 , further comprising applying an overcoat layer over the layer of silver cladding. 
     
     
         20 . The process of  claim 19 , wherein the overcoat layer is a crosslinked polysiloxane, a crosslinked poly (silsesquioxane), or a crosslinked layer comprising poly(vinylphenol) and a melamine-formaldehyde resin.