Resistive heater

Abstract

A composite formulation of the present disclosure may have conductive properties (i.e. low resistance), such that the formulation may be used in resistive heating applications. The composite may have one or more matrix materials and one or more conductive fillers. The composite may be used in the formation of resistive heaters having a number of layers, including a conductive layer, the conductive layer including the composite. Heaters of the present disclosure may be used for a number of applications including ground, floor, or roof heating, or laboratory equipment heating.

1 - 20 . (canceled) 
     
     
         21 . A resistive heater comprising:
 a substrate layer;   an electrically and thermally conductive layer over the substrate layer, the electrically and thermally conductive layer comprising a composition including:
 50-99% by weight of a matrix material; and 
 at least two conductive fillers selected from carbon nanotubes, carbon fibers, and graphite flakes, each of the at least two conductive fillers provided in an amount greater than 0% and less than 50% by weight; and 
   a pair of electrical connectors connected to the electrically and thermally conductive layer.   
     
     
         22 . The resistive heater of  claim 21 , wherein the at least two conductive fillers are dispersed throughout the electrically and thermally conductive layer. 
     
     
         23 . The resistive heater of  claim 21 , wherein the at least two conductive fillers are distributed in a pattern throughout the electrically and thermally conductive layer. 
     
     
         24 . The resistive heater of  claim 23 , wherein the electrically and thermally conductive layer comprises a pattern of at least one zone of the at least two conductive fillers and at least one zone without conductive fillers. 
     
     
         25 . The resistive heater of  claim 21 , further comprising a heated layer over the electrically and thermally conductive layer. 
     
     
         26 . The resistive heater of  claim 25 , wherein the heated layer is electrically non-conductive. 
     
     
         27 . The resistive heater of  claim 26 , wherein the heated layer is thermally conductive. 
     
     
         28 . The resistive heater of  claim 26 , wherein the heated layer has properties for thermal emissivity. 
     
     
         29 . The resistive heater of  claim 21 , further comprising a controller electrically connected with the pair of electrical connectors to regulate power to the conductive layer. 
     
     
         30 . The resistive heater of  claim 29 , wherein the controller comprises a wireless connectivity device, such that the controller can be operated remotely and wirelessly. 
     
     
         31 . A method for manufacturing a resistive heater, the method comprising:
 pouring or spraying an electrically and thermally conductive layer over a substrate layer, the electrically and thermally conductive layer comprising a composition including:
 50-99% by weight of a matrix material; and 
 at least two conductive fillers selected from carbon nanotubes, carbon fibers, and graphite flakes, each of the at least two conductive fillers provided in an amount greater than 0% and less than 50% by weight; 
   connecting the electrically and thermally conductive layer to a controller via one or more conductors, wherein the controller regulates power to the resistive heater; and   drying or curing the electrically and thermally conductive layer.   
     
     
         32 . The method of  claim 31 , wherein the matrix material comprises chlorobutyl rubber. 
     
     
         33 . The method of  claim 31 , further comprising providing a heated layer over the electrically and thermally conductive layer. 
     
     
         34 . The method of  claim 33 , wherein the heated layer is electrically non-conductive. 
     
     
         35 . The method of  claim 34 , wherein the heated layer is thermally conductive. 
     
     
         36 . The method of  claim 34 , wherein the heated layer has properties for thermal emissivity. 
     
     
         37 . A sprayable, moldable, castable, or pourable composite formulation comprising:
 50-99% by weight of a matrix material; and   at least two conductive fillers selected from carbon nanotubes, carbon fibers, and graphite flakes, each of the at least two conductive fillers provided in an amount greater than 0% and less than 50% by weight; and   
     
     
         38 . The composite formulation of  claim 37 , wherein the composite formulation is viscous prior to curing or drying. 
     
     
         39 . The composite formulation of  claim 37 , further comprising more than 0% and up to 5% by weight of stearic acid. 
     
     
         40 . The composite formulation of  claim 39 , further comprising more than 0% and up to 5% by weight of a defoaming agent.