▎ 摘　　要

NOVELTY - Graphene modified aqueous epoxy resin coating comprises 53% solid content component A and 40% solid content component B. The preparation comprises mixing component A and component B at 1.5-4:1, adding deionized water and mixing. The component A is graphene-modified aqueous epoxy resin emulsion. The preparation of component A comprises adding 0.1-1% graphene derivative to aqueous epoxy resin emulsion, dispersing and emulsifying bisphenol A epoxy resin with emulsifier. The component B is amine-based aqueous epoxy curing agent. USE - Graphene modified aqueous epoxy resin coating used for coating metal substrate e.g. carbon steel plate, electrogalvanized steel plate, galvanized steel plate, hot-dip galvanized steel plate or aluminum alloy plate (claimed). ADVANTAGE - The coating has safe preparation and is environmental friendly and free from heavy metal ions and volatile organic solvents. DETAILED DESCRIPTION - Graphene modified aqueous epoxy resin coating comprises 53% solid content component A and 40% solid content component B. The preparation comprises mixing component A and component B at 1.5-4:1, adding deionized water and mixing. The component A is graphene-modified aqueous epoxy resin emulsion. The preparation of component A comprises adding 0.1-1% graphene derivative to aqueous epoxy resin emulsion, dispersing and emulsifying bisphenol A epoxy resin with emulsifier. The component B is amine-based aqueous epoxy curing agent. The preparation of graphene derivative comprises oxidizing expanded graphite to graphite oxide using modified Hummers method, dispersing graphite oxide in deionized water, peeling off graphene oxide by ultrasonic or mechanical stirring, performing hydroxylation pre-reduction on the surface of the graphene oxide at 300 W for 10-25 minutes, dispersing ultrasonic dispersion in water to obtain 1 mg/ml brown graphene oxide dispersion, adjusting pH to 8-11 using 5% sodium carbonate aqueous solution, adding 0.04 mg/ml sodium borohydride aqueous solution to obtain mixed solution, reacting at 70-80 degrees C at 200-600 revolutions per minute for 1-2 hours, filtering, washing with deionized water, dispersing in deionized water to obtain 2 mg/ml hydroxylated graphene dispersion, reacting in ice bath for 1-3 hours to obtain aminodiazonium salt solution, performing sulfonation modification on the surface of the graphene oxide, adding diazonium salt solution to the hydroxylated graphene dispersion, reacting for 2-8 hours at 0 degrees C, filtering, washing cake with deionized water, dispersing sulfonated graphene oxide, adding diazonium salt solution to the hydroxylated graphene dispersion, reducing sulfonated graphene oxide, adding hydrazine hydrate, reacting at 80-100 degrees C for 10-30 minutes, filtering and washing filter cake with deionized water.