AQUEOUS DISPERSION OF HYBRID PARTICLES CONSISTING OF ORGANIC OR INORGANIC PIGMENT PARTICLES AND ORGANIC NANO-PARTICLES AND PROCESS FOR PREPARING THE SAME

摘要

An aqueous dispersion of hybrid particles consisting of inorganic or organic pigment particles and organic nano-particles attached to the surface of the pigment particles, the nano-particles having a particle size between 2 and 200 nanometers. Preferably the nano-particles have a glass transition temperature of at least 120 °C and comprise co-polymers of vinyl monomers and a mixture comprising maleic anhydride and derivates of maleic anhydride. In a process for preparing such an aqueous dispersion a copolymer of vinyl monomers and maleic anhydride is treated in water with a compound having the general formula R-N H2 of which R is H, alkyl with 1 to 18 C-atoms or aryl, and in the presence of one or more inorganic pigment particles, at least 35 % of the maleic anhydride groups being transformed in imides groups.