Preparation and Application of High Near‐Infrared Reflective Green Pigment for Ceramic Tile Roofs

Abstract

Complex inorganic green pigments having a high near‐infrared (NIR) solar reflectance were synthesized. Chromium oxide (Cr 2 O 3 ) was used as the host component with mixtures of TiO 2 , Al 2 O 3 , and V 2 O 5 as the guest components. TiO 2 , Al 2 O 3 , and V 2 O 5 were mixed into 39 different compositions. It was found that a sample, denoted by S9, with the composition of Cr 2 O 3 , TiO 2 , Al 2 O 3 , and V 2 O 5 are 80, 4, 14, and 2 wt%, respectively, gives a maximum NIR solar reflectance of 82.8% compared with 69.6% of a commercially available cool pigment powder. The comparison study on the effectiveness of the synthesized pigment and a commercial pigment on ceramic glaze and sprayed on ceramic tile roofs show that the new powder has given a better result by keeping the tested room about 2°C cooler. It can be concluded that the new formulated green pigment is a highly thermal effective as an NIR reflective roof coating.