Study On Low Infrared Emissivity Properties Compatible With Low Glossiness Of Composite Metal Pigments/PU Coatings

At present, Al powders was widely used at home and abroad as metal pigments to prepareinfrared low emissivity coatings, but the metallic luster of Al making the low-emissivity coatingsshowing a high glossiness, which go against the visible light stealth, adding traditional matting agentsuch as SiO2, TiO2to coatings can reduce the glossiness while make emissivity increase. Therefore,the development of low emissivity and low glossiness compatible coatings has important theoreticaland practical significance.In this paper, factors affecting emissivity and glossiness were analysed systematiclly, andstructure model of low emissivity coatings compatible with low glossiness was designed by theory.Single filler was replaced by composite metal pigments according to extinction principle and thetheory of composite metal pigments can prepare low emissivity coatings, and the rules and methods toprepare low emissivity and low glossiness compatible coatings were explored systematically, finallythe compatible coatings were prepared with excellent comprehensive properties. The mainconclusions are as follows:1. The structure model of low emissivity coatings compatible with low glossiness was designedaccording to systematiclly analysis the relationship between the filler, binder and micro structure withemissivity and glossiness, according to the mechanism of traditional extinction and impact ofcomposite metal pigments on emissivity, the experimental scheme was designed to prepare lowemissivity and low glossiness compatible coatings by composite metal pigments.2. The composite scheme of aluminum with different floating rate was designed and the possibleresult was predicted through the microscopic simulation diagram, the final experimental scheme wasthe composite of high floating rate aluminum with floating rate aluminum and the composite of twodifferent types of floating rate aluminum, and the compatible of low emissivity and low glossinesscoatings were prepared. The glossiness of the coating prepared by the composite of high floating ratealuminum with floating rate aluminum basically unchanged while the emissivity decreased, however,the emissivity and glossiness of the coating prepared by the composite of two different types offloating rate aluminum both decreased, the emissivity and glossiness can be as low as0.194and18.4%, and the principle was explained reasonably through the optical theory.3. The experimental scheme was designed including the composite of Ag powders with Alpowders and the composite of Cu powders with Al powders according to analysis the relationship between emissivity and conductivity of metals, and the compatible of low emissivity and lowglossiness coatings were prepared. The glossiness of the coating prepared by the composite of Agpowders with Al powders basically unchanged while the emissivity decreased, however, theemissivity and glossiness of the coating prepared by the composite of Cu powders with Al powdersboth decreased, the emissivity and glossiness can be as low as0.103and16%, and the principle wasexplained reasonably through the optical theory.4. The coatings with excellent compatible performance of low emissivity and low glossinesswere chosen to test the mechanical properties and corrosion resistance, the results show that coatingsprepared by composite metal pigments have excellent mechanical properties and corrosion resistanceexcept the coating prepared by composite of Cu powders with Al powders, this laid the foundation forthe future engineering application.