▎ 摘　　要

NOVELTY - A graphene modified cathode polyurethane electrophoretic resin comprises 0.01-1 wt.% graphene, 10-14 wt.% oligomer polyol, 40-50 wt.% isocyanate, 0.8-1.2 wt.% trimethylolpropane, 10-18 wt.% hydrophilic agent, 10-18 wt.% chain extender, and 3-11 wt.% neutralization salt-forming agent. USE - Graphene modified cathode polyurethane electrophoretic resin of electrophoretic coating composition for producing electrophoretic coating film (all claimed). ADVANTAGE - The graphene modified cathode polyurethane electrophoretic resin has excellent anticorrosive performance and conductivity, prolongs the service life of the electrolyte, and is economical. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation method of graphene modified cathode polyurethane electrophoretic resin, which involves (1) ultrasonically processing oligomer polyol, trimethylolpropane, and graphene at 25-35 degrees C for 0.5-6 hours, and dehydrating at 85-95 degrees C for 1-2 hours, (2) dripping isocyanate with a constant pressure funnel, and polymerizing at 75-80 degrees C for 2.5-3.5 hours, (3) dissolving hydrophilic agent in 1,4-dioxane, dripping the mixed liquid obtained in step (2), and reacting at 25-35 degrees C for 2-4 hours, and (4) dissolving chain extender in 1,4-dioxane, dripping the mixed liquid obtained in step (3), and reacting at 75-85 degrees C for 2.5-3.5 hours, and (5) adding neutralization salt-forming agent, and reacting at 20-35 degrees C for 1-2.5 hours; (2) electrophoretic coating composition which comprises 24.40-26.03 wt.% graphene modified cathode polyurethane electrophoretic resin, 5.61-6.86 wt.% end capped isocyanate, 0.74-0.78 wt.% propylene glycol phenyl ether, and 66.33-69.6 wt.% deionized water; and (3) use of electrophoretic coating composition in production of electrophoretic coating film, which involves mixing and stirring graphene modified cathode polyurethane electrophoretic resin, end capped isocyanate, and propylene glycol phenyl ether for 1-2 hours, dripping deionized water, high speed shearing in water to form emulsion, after electrophoresis film, baking in oven, and secondary crosslinking the wet film.