NIR Absorber - functional nano-additives for inks and coatings

 
Inorganic colour pigments are part of paint formulations since the early days. The attention for colour pigments was focussed on their properties in the visible light. Recently the colour pigment properties in the Near Infrared Light attracted attention. Manipulation of pigment properties in the wavelength range of 800 - 2500 nm lead to the development of NIR reflecting colour pigments, which give surfaces a reduced heat load. NIR Absorbers on the other hand are designed in a way to provide high transparency in the visible light range and a high absorption from 800 nm - 2500 nm. Those products are based on Antimony Tin Oxide, Indium Tin Oxide, Tungsten Oxides or Copper Compounds. Each group of pigments has specific advantages for different coating and ink applications. The most prominent application is for transparent coatings on glass or polymeric windows for heat protection applications. Additionally the NIR absorber are valuable additives for ink formulations for example for 3D printing inks, for security inks or for drying accelerators in water-based, NIR dried inkjet inks. Examples for formulation and performance will demonstrate the versatility of the new additives.