Preparation and performance tuning of brown soil-colored laser and visible light multi-spectral compatible stealth coatings

A high-performance laser and visible light multi-spectral compatible stealth coating with brown earth color characteristics was prepared using graphite as the near-infrared absorbing filler, medium chrome yellow inorganic pigment as the colorant, and polyurethane resin as the binder. The effects of graphite particle size, mass ratio of graphite to medium chrome yellow pigment, and total pigment-filler content on the coating color, near-infrared reflectance and mechanical properties were systematically investigated. The results show that when the graphite particle size is 4000 mesh, the mass ratio of graphite to medium chrome yellow is 3:7, and the total pigment-filler content is 20 wt. %, the coating exhibits a grade 1 adhesion strength, 2 mm flexibility, and impact resistance up to 50 kg·cm. Meanwhile, the reflectance of the coating at 1.06 μm near-infrared light is as low as 3.27%. By adjusting the mass ratio of graphite to medium chrome yellow pigment, the color characteristics of the coating can gradually approach the standard brown earth color BE0811, with the color difference value less than 3. The as-prepared coating shows promising application prospects in the multi-spectral compatible camouflage design of various land-based equipment.