▎ 摘　　要

NOVELTY - A graphene paste is an aqueous dispersion formed by dispersing modified graphene in water. The ratio of modified graphene and water is 2-20 mg:1 ml. The modified graphene is obtained by adding graphene oxide into water to obtain a graphene oxide aqueous dispersion with a concentration of 1-4 mg/ml, adding carbodiimide to obtain the mixed solution by Hummers process, adjusting the pH value of the mixed solution to 10-12 with 2-5 vol.% aqueous ammonia solution, reacting at 50-90 degrees C for 5-24 hours, centrifuging or filtering, and washing the precipitate or filter cake with deionized water. USE - Graphene paste is used for cationic aqueous polyurethane paint (claimed). ADVANTAGE - The graphene paste is environmentally-friendly, and has excellent long-term storage stability of 1 year at room temperature and elastic modulus of 2.2-2.31 GPa, suppressed generation of precipitation, flocculation and gelation. The neutral spray time of 72-120 hours. DETAILED DESCRIPTION - A graphene paste is an aqueous dispersion formed by dispersing modified graphene in water. The ratio of modified graphene and water is 2-20 mg:1 ml. The modified graphene is obtained by adding graphene oxide into water to obtain a graphene oxide aqueous dispersion with a concentration of 1-4 mg/ml, adding carbodiimide to obtain the mixed solution by Hummers process, adjusting the pH value of the mixed solution to 10-12 with 2-5 vol.% aqueous ammonia solution, reacting at 50-90 degrees C for 5-24 hours, centrifuging or filtering, and washing the precipitate or filter cake with deionized water until is neutral. The carbodiimide is commercially available carbodiimide aqueous dispersion or emulsion-based carbodiimide. The weight ratio of carbodiimide and graphene oxide is 5-20:1. An INDEPENDENT CLAIM is included for usage of graphene paste in cationic aqueous polyurethane paint.