▎ 摘　　要

NOVELTY - A metal printing ink comprises 15-25 pts. wt. aqueous polyurethane resin, 30-45 pts. wt. polypropylene resin, 20-30 pts. wt. aqueous acrylic acid resin, 5-20 pts. wt. soybean oil, 15-25 pts. wt. metal pigment, 5-15 pts. wt. isopropanol, 1-5 pts. wt. chitosan-graphene composite, 1-5 pts. wt. additive, 1-5 pts. wt. hollow glass microspheres, and 1-2 pts. wt. walnut powder. USE - Metal printing ink (claimed). ADVANTAGE - The metal printing ink has excellent boiling-water resistance and salt fog resistance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of metal printing ink, which involves uniformly mixing soybean oil and isopropanol, adding aqueous polyurethane resin, polypropylene resin, and aqueous acrylic resin, uniformly mixing and dispersing, grinding, adding chitosan-graphene composite, ultrasonically processing for 30-40 minutes, adding the remaining raw materials, and stirring uniformly.