Preparation and using of high near-infrared reflective green pigments on ceramic glaze

Complex inorganic green pigments having a high near infrared solar reflectance have been synthesized. Cr2O3 is the host component and mixtures of TiO2, Al2O3, and V2O5 were used as the guest components. TiO2, Al2O3 and V2O5 were mixed into 39 different compositions. It was found that a sample, denoted by S9, with a composition of Cr2O3, TiO2, Al2O3 and V2O5 of 80, 4, 14 and 2 wt% respectively, gives a maximum near infrared solar reflectance of 82.8%. The S9 pigment powder was then prepared as a reflective coating material with different amounts of pigment powder from 4-8g in 100 g of ceramic glaze. The prepared materials were sprayed on the clay tiles for reflectance measurements. It was found that 6g of S9 pigment powder mixed with 100 g of ceramic glaze gives the highest near-infrared reflectance value of 74.5%. The newly synthesized pigment is a suitable ceramic roof coating for its high reflectance performance and the durability performing once the ceramic roof installed on house. (C) 2010 The Ceramic Society of Japan. All rights reserved.