Two common types of pigment dispersants

There are two types of dispersants for general pigment inks: anionic wetting and dispersing agents, cationic wetting and dispersing agents, nonionic wetting and dispersing agents, amphoteric wetting and dispersing agents, and electrically neutral wetting and dispersing agents. Most of them are composed of non-polar negatively charged lipophilic hydrocarbon chain segments and polar hydrophilic functional groups. Two types of functional groups are located at both ends of the molecule, forming an asymmetric hydrophilic and oleophilic molecular structure. Its varieties include sodium oleate, carboxylate salts, sulfate salts, sulfonate salts, etc. Anionic dispersants have good compatibility and are widely used in water-based coatings and inks.

Today, the editor of Jianyi Chemical will talk about two common types of pigment dispersants.

1. Anionic type, utilizing the principle of mutual repulsion of the same charge (negative charge), causes pigment particles with anionic dispersants to repel each other, making it difficult for them to aggregate into larger particles and precipitate.

2. Non ionic dispersants cause particles to shift away from each other when pigment particles with negative charge dispersants approach and may aggregate. This function is called steric hindrance.

All dispersion systems are designed using the above principles, and well dispersed inks have significantly improved flowability, rheology, color development, coverage, and glossiness. During the use or storage of ink, its stability will also be relatively improved, and the precipitation/delamination phenomenon will be reduced.