Organic pigments in the surface treatment process, in order to make its particle surface polarity and the use of dispersed media (such as connecting materials or pigments, organic solvents) have good compatibility or matching, need to add surface treatment agent or coating agent, it is often first to add a surface modifier with a specific substituent (e.g. sulfonic acid base, amino, etc.), adsorbed on the surface of the particle, and then add the surface treatment agent, so that it and surface modifier with chemical bond, ion pair or hydrogen bonding, etc. Finally, the surface treatment agent is more firmly adsorbed on the pigment surface to achieve the modification of pigment particles.
The commonly used surface modifiers include silane coupling agent, titanate coupling agent, aluminate coupling agent and stearic acid.