Preparation and properties of multi-color coatings with ultra-low near-infrared reflectivity

Abstract

In this paper, a high-performance laser and visible multi-spectrum compatible stealth coating with brown earth color and medium green color was prepared by using graphene as laser absorbing pigment, earthy yellow and medium yellow color pastes as coloring pigments, and polyurethane (PU) as adhesive, respectively. The effects of graphene addition amount, type and content of coloring pigment on the color, 1.06 μm near-infrared reflectivity, and mechanical properties of the coating were systematically studied. The results indicate that graphene was used as the laser absorbing pigment to effectively reduce the spectral reflectivity of the coating at the wavelength of 1.06 μm. With the increase of graphene content, the reflectivity of the coating to 1.06 μm near-infrared light decreases first and then increases slightly. When the graphene content is 4 wt%, the reflectivity of the coating to 1.06 μm near-infrared light can be reduced to 3.0 %, which achieves the performance requirement of ultra-low near-infrared reflectivity and makes the coating have outstanding laser stealth performance. When the amount of graphene is 4 wt%, earthy yellow and medium yellow color pastes are used as the coloring pigments. With the increase of the color paste addition, the coating can gradually show the color characteristics of earth and green. When the mass ratio of graphene to the two color pasts is 1:10, the two coatings prepared have bright brown earth color and medium green color characteristics, respectively, and the reflectivity of the coatings to 1.06 μm near-infrared light can be as low as less than 10 %, which well meets the requirements of laser and visible light compatible stealth. In addition, the prepared coating has excellent mechanical properties.