A high-purity, highly dispersible boehmite-type nano alumina produced by a special synthesis route. Without any physical or chemical pre-treatment it disperses in water to form a stable, uniform system. Its main use is as the inorganic filler of the ink-receiving layer in water-based colour inkjet media, where it markedly raises ink absorption speed, drying performance and colour saturation while improving coating whiteness and hand feel. Dispersion is simple: add the powder to water and disperse for about 40 minutes to obtain a uniform, stable hydrosol of the required solids; low-molecular-weight PVA such as BP-24 or BP-224 can be used as binder. Store sealed and dry. It is a non-toxic nano powder, but prolonged contact with high dust concentrations may irritate skin and eyes, so direct contact should be avoided during transport and use; a mask and goggles are recommended.
