Studies On Pigment Dispersion And Binder Stability In Printing Ink

The wettability and dispersion of pigment, which is directly related to quality of ink in production, play a key role in printing ink production. Therefore, analyzing on wettability and dispersion of pigment in ink is an important project. In this work, the wettability of pigments in linseed oil was studied by static adsorption method and the wettabilities of different pigments were qualitatively determined. The results will play an important theoretical guiding role in printing ink designing and testing.The copper phthalocyanine (CuPc) is one of important organic pigments, but the application of this kind of pigment is restricted due to its poor wettability in water. With people's increased awareness of protecting the environment, more and more researchers are interested in the surface-modifying treatment of organic pigments. The nano-silica encapsulated pigments were prepared by sol/gel method and were characterized by using DLS, SEM, TEM, FTIR, and XPS. The results reveal that the thermal stability, wettability, dispersion in water of the encapsulated pigments can be greatly improved by the coating of nano-silica on the surface of pigments.The ink binder is a very important part in ink system. The viscosity, liquidity and drying of printing ink is decided by quality of ink binder. Therefore, the stability of ink binder has great influence on the quality of ink. In this work, the mechanism of turbidity of ink binder was studied. A series of ternary component diagram of ink binders with different components and composite ratios at different storage temperatures can be obtained. Polarizing microscopy and infrared spectrum analysing showed that the components in the turbid samples were unchanged but formed different shapes crystals. The results give us a further understanding the turbidity of ink binder system.