Multilayer Electrical Component, Coating Composition, and Method of Making Electrical Component

Abstract

An electrical component including a substrate comprising an electroconductive filler in a first polymeric binder, and a coating layer adhered to at least a portion of the substrate surface, the coating layer comprising a nanostructured electroconductive particulate dispersed in a polymeric binder, such as an epoxy resin. A method of making the component also is described.

What is claimed is: 
     
         1 . A method comprising:
 obtaining a substrate comprising a plurality of electroconductive filler fibers in a polymeric binder,   dispersing a nanostructured electroconductive particulate filler in a liquid comprising at least one of a solvent and a reactive diluent to form a dispersion,   mixing the dispersion with a liquid resin to form a coating mixture,   applying the coating mixture to the substrate, and   crosslinking the applied coating mixture to form a coated substrate.   
     
     
         2 . The method of  claim 1 , wherein the nanostructured electroconductive particulate filler comprises at least one member selected from the group consisting of carbon nanotubes, boron nitride nanotubes, metal nanoparticles, metal oxides, and crushed fibers. 
     
     
         3 . The method of  claim 1 , wherein the liquid includes a reactive diluent, and the reactive diluent comprises a diglycidyl ether of a diol. 
     
     
         4 . The method of  claim 1 , further comprising adding a crosslinking agent to the mixture containing the dispersion and the uncrosslinked resin. 
     
     
         5 . The method of  claim 1 , wherein the coating mixture is applied by at least one of dipping, spray coating, spin coating, transfer coating, kiss coating, pad coating, and roll coating. 
     
     
         6 . The method of  claim 1 , wherein the polymeric binder and the resin comprise epoxy. 
     
     
         7 . The method of  claim 1 , wherein the coating layer contains at least 0.5 wt % nanostructured electroconductive particulate filler. 
     
     
         8 . The method of  claim 1 , wherein the resin comprises at least one member selected from the group consisting of epoxies, acetals, ionic and non-ionic polyurethanes, polyimides, polyesters, silicones, ionic and non-ionic synthetic rubbers, ionic and non-ionic natural rubbers, polyether sulfones, polysulphones, polybutylphthalates, polyether ether ketones, polyether imides, polystyrenes, polyolefins, polyethylene terephthalates (PETs), polyamides, polyvinyl chlorides, polyphenylene oxides, polycarbonates, acrylonitrile-butadiene-styrene terpolymers, fluoropolymers, and blends and copolymers thereof. 
     
     
         9 . The method of  claim 1 , wherein the substrate contains about 80 to about 98 parts by weight electroconductive filler fibers based upon 100 parts by weight of the polymeric binder and the electroconductive filler fibers. 
     
     
         10 . The method of  claim 1 , wherein the electroconductive filler fibers in the substrate comprise aligned fibers. 
     
     
         11 . The method of  claim 1 , wherein the electroconductive filler fibers in the substrate comprise aligned carbon fibers. 
     
     
         12 . The method of  claim 1 , wherein the polymeric binder in the substrate comprises at least one member selected from the group consisting of epoxies, acetals, polyesters, rubbers, polyurethanes, polyether sulfones, polysulphones, polybutylphthalates, polyether ether ketones, polyether imides, polystyrenes, polyethylene terephthalates, polyamides, polyimides, polyvinylchlorides, polyphenylene oxides, polycarbonates, acrylonitrile-butadiene-styrene terpolymers, silicones, fluoropolymers, and polyolefins. 
     
     
         13 . The method of  claim 1 , further comprising forming a sleeve layer over a portion of the coated substrate. 
     
     
         14 . The method of  claim 1 , wherein the coating layer has a thickness of no more than  2 mm after crosslinking. 
     
     
         15 . The method of  claim 1 , wherein the nanostructured electroconductive particulate filler comprises carbon nanotubes. 
     
     
         16 . The method of  claim 2 , further comprising adding a secondary filler to the liquid comprising at least one member selected from the group consisting of a strengthener, a scratch preventer, a surface friction reducer, a hardness controlling additive, a contamination preventer, a corrosion preventer and a coloring agent. 
     
     
         17 . The method of  claim 1 , wherein the polymeric binder and the resin comprise the same polymer. 
     
     
         18 . The method of  claim 1 , further comprising an electrical component wherein the surface resistance of the crosslinked coating mixture is the same as the bulk resistance of the substrate. 
     
     
         19 . The method of  claim 1 , wherein the crosslinked coating mixture contains about 2 to about 20 wt. % filler. 
     
     
         20 . The method of  claim 1 , wherein the polymeric binder and the resin comprise the same polymer. 
     
     
         21 . The method of  claim 1 , wherein the electroconductive filler fibers in the substrate comprise aligned carbon fibers, and the polymeric binder in the substrate comprises at least one member selected from the group consisting of epoxies, acetals, polyesters, rubbers, polyurethanes, polyether sulfones, polysulphones, polybutylphthalates, polyether ether ketones, polyether imides, polystyrenes, polyethylene terephthalates, polyamides, polyimides, polyvinylchlorides, polyphenylene oxides, polycarbonates, acrylonitrile-butadiene-styrene terpolymers, silicones, fluoropolymers, and polyolefins.