Research On Waterborne Solar-Reflective Heat-Insulating Coatings

The waterborne solar-reflective heat-insulating coatings can reduce internal surrounding excessive temperature rise of materials. Wide uses of the waterborne solar-reflective hea-insulating coatings can improve work environments and save energy. Studies and development on the waterborne solar-reflective heat-insulating coatings have profound significance.According to MIL-E-46136, testing device for solar heat-reflective insulating coatings was made to test heat insulation. Appling the improved testing device, the influence of resin kind, pigment, filling kind and proportion, pigment/binder ratio, colors and the coating thickness on coating performance was researched and discussed. Finally the infra-red spectrogram and heat reflectivity of the waterborne solar-reflective hea-insulating coatings were researched to characterize the heat insulation.The experimental results showed: The influence of the pigment and resin on the property of thermal-insulation is important. The transparence of the water-soluble polyacrylate resin is high, and its refraction modulus is low. Moreover, the polyacrylate contains no functional groups which can absorb heat, which make the property of thermal-insulation better. Therefore, the water-soluble polyacrylate resin was used in the research. The mixture of hollow ceramic micro spheres and rutile TiO₂ can make the property of thermal-insulation much better. The barium sulfate can be used as substitute of rutile TiO₂, and property of thermal-insulation is good enough, which make the cost of the coatings low. According to the experimental results, the mass ratio of rutile TiO₂, barium sulfate, mica and hollow ceramic micro spheres is 1～4: 1～4: 1～2. The waterborne solar-reflective heat-insulating coatings were prepared using water-soluble polyacrylate resin, rutile TiO₂, mica, barium sulfate, water, additives, and hollow ceramic micro spheres. The heat reflectivity of the waterborne solar-reflective hea-insulating coatings using on the metal is 92%. The heat reflectivity of the waterborne solar-reflective hea-insulating coatings using on the buildings is 91%, which is comparable to the hea-insulating coatings of THERMO-SHIELD whose heat reflectivity is 90%.