Unique Rare Earth Pigments for More Thermally Comfortable Leathers

Abstract

This paper reports the investigations carried out on the synthesis characterization and optical properties of a new class of rare earth based near infrared reflective yellow pigments as an alternative to toxic inorganic pigments. The rare earth yellow pigments can be prepared by employing calcination method. The present work reveals that the doping of molybdenum for ceria in gadolinium cerium lattice changes the color hue from cream white to dark yellow. The calcination temperature employed for preparation of these pigments was about 1000°C. This temperature was found to be much lower than that required to achieve the intense yellow hue through conventional solid state calcinations reaction (above 1500°C). X-ray diffraction data confirm the crystalline character of the pigments. The pigment thus developed serves as a potential candidate for NIR reflective pigments for leather applications on account of its NIR reflectance value of 96% in the wavelength region 1100 nm. Thermal images of the finished leather exposed to NIR light clearly indicate the lower heat retention character. The pigment properties were in good agreement with industrial requirements. They also serve as environmentally safer pigments.