Preparation and characterization of nanopigments by wet milling technique and their applications in printing ink industry

Abstract

Preparation and characterization of nanopigments by wet milling technique and their applications in printing ink industry This study focused on preparation of four colors process sheet fed offset inks (yellow-magenta-cyan-black) by top-bottom technique until reach the nano sized also corresponding traditional inks were prepared in order to compare the physical and optical ink properties to study the benefits of nano inks. In the first part of this study, grinding varnish was prepared in a closed kettle and physical properties as viscosity, yield value and tack were measured with the suitable apparatus. Using the prepared grinding varnish, many mill base recipes were created for each color with different ratios of dispersing agents and milling time in order to study their effects on the particle size reduction and also traditional mill base was prepared under the conventional condition. Using the dyno mill machine (Eiger torrence), the mill base samples were milled under controlled factors as tip speed and temperature. Depending on the fact that as the particle size of pigment decrease the pigment color strength increase, Tinting strength test was applied for all prepared nano samples and compared with traditional sample to indicate the best sample in color strength, then the best sample was diluted and its morphology was analyzed using TEM apparatus which ensure reaching the nano scale, also the traditional mill base was introduced to the TEM test which was in the micron range.