Enhancement of filtration and dispersion properties of Pigment Yellow 14 via an in situ coating strategy onto ethylene–vinyl acetate wax

The masterbatch technology is a traditional pre-dispersing way of pigments, but it needs drying and well-dispersing pigments and subsequent complicated procedures to prepare masterbatch. Due to the aggregation phenomenon of pigments during drying, the pulverization of chunks formed will lead to serious energy consumption and dust pollution. In addition, the subsequent masterbatch preparation including some complicated procedures, also causing the consumption of time, machines and energy. In order to overcome these issues, a new in situ coating strategy to pre-disperse pigment was developed in this work. The hydrophobic ethylene–vinyl acetate copolymer wax was covered with Pigment Yellow 14 (PY14), forming pre-dispersed E-PY14 with the uniform core–shell structure and enhanced hydrophobic properties. Compared with the masterbatch pre-dispersion technique, the in situ coating method can avoid the complicated processes such as filtration, kneading and extrusion. The obtained E-PY14 could be easily separated from water, and the filtration time and water content of the filter cake were reduced by 96.25% and 27%, respectively. Besides, the dispersibility of the pigment in resin was remarkably improved, verified with the decrease in the filter pressure value from 0.75 to 0.06 MPa/g. As the obtained E-PY14 do not need to be strongly pulverized, it can also inhibit dust pollution. We believe that the developed in situ coating approach will bring inspiration to the pre-dispersion technology of pigments. Graphical abstract