▎ 摘　　要

NOVELTY - Electric heating composite material comprises functional filler and high temperature resistant resin, where the functional filler comprises graphene, bismuth (III) oxide and ruthenium (IV) oxide, and the high temperature resistant resin is synthetic silica sol. USE - The electric heating composite material is useful in electrothermal film (claimed), and also used in industrial tunnel type IR drying tunnel, industrial electronic precision oven, continuous baking varnish production drying lines, food baking ovens and other industrial large power heating field. ADVANTAGE - The method solves technical problems of low electrothermal radiation efficiency, uneven surface temperature, complex preparation process and harsh process conditions of graphene electric heating materials in the prior art. The electric heating composite material has huge market prospects. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing electric heating composite material, comprising (1) adding 80 mesh graphite powder into concentrated sulfuric acid under the condition of 10-15degrees Celsius, adding potassium permanganate, mechanically stir for 120 minutes, heating to 90degrees Celsius, adding deionized water and hydrogen peroxide with concentration of 30%, mechanical stirring for 30 minutes, and washing the precipitate to obtain graphene oxide, placing the graphene oxide in three-necked flask, adding distilled water, ultrasonically dispersing for 20 minutes, adding sodium borohydride, heating in water bath at 75degrees Celsius for 150 minutes, washing and drying to obtain graphene, where the weight ratio of the graphite powder, concentrated sulfuric acid, potassium permanganate, deionized water and hydrogen peroxide is 1:20-27:2-2.5:130-150:8-10, and the mass ratio of the graphene oxide, distilled water and sodium borohydride is 1:1000:28-32, (2) adding the graphene into the surfactant aqueous solution, uniformly dispersing, dropping 0.1 mol/l ruthenium (III) chloride aqueous solution and 0.2mol/l bismuth(III) nitrate aqueous solution under mechanical stirring, and then use 0.5mol/l sodium hydroxide aqueous solution to adjust the pH value to 7-8, continuously mixing for 45 minutes, filtering and washing with water, heating in 200degrees Celsius air atmosphere for 300 minutes to obtain graphene/bismuth(III) nitrate/ruthenium (IV) oxide functional filler, where the mass ratio of the graphene, ruthenium (III) chloride and bismuth(III) nitrate is 10:0.15-0.25:0.3-0.6, the surfactant is mixture of polyethylene glycol and glycerol, and the mass ratio of graphene, polyethylene glycol and glycerol is 1:1-3:0.3-0.5, (3) mixing methyl trimethoxy silane, water, methanol and 0.5 mol/l aqueous hydrochloric acid solution, and stirring mechanically for 300 minutes to obtain synthetic silica sol, where the molar ratio of the methyl trimethoxy silane, water, methanol and hydrochloric acid is 1:6-8:7-8:0.002-0.01, and (4) mixing the graphene/bismuth(III) nitrate/ruthenium (IV) oxide functional filler, attapulgite, fluorocarbon surfactant, silicone defoamer and water, and grinding at high speed for 200 minutes to obtain functional slurry, adding synthetic silica sol, sodium benzoate preservative and polyether modified organosilicone flatting agent, and mechanically stirring the mixture to obtain electric heating composite material.