Infrared Reflective Inorganic Pigments

Solar energy is essential for human race. It spreads itself thin on the entire surface of the globe. The large buildings, which are now essential for the world's growing population, need to be made comfortable for its residents. In certain parts of the year these radiations are not required for the comfort of the residents. If the buildings are allowed to receive these radiations, the expenditure of cooling is excessive. Coatings that reflect the infrared radiation in the near IR region responsible for heat from the solar radiation are formulated with special pigments. In the present paper, patents devoted to preparation of these pigments have been reviewed. Some research work carried out at University Institute of Chemical Technology has also been included. It has been found that there are no theories to predict the infrared reflectivity of a pigment and the best way to find one is to scan the available pigments for their IR reflectivity.