Pigment Wetting Agents & Dispersants
What Are Pigments?
Pigments are insoluble, solid powders that provide color to various materials, such as coatings, paints, and inks. Though they are commercially available in a wide range of chemistries and colors, pigments must be properly dispersed to provide optimal performance and appearance.
What Is Involved in The Pigment Dispersion Process?
1.????? Pigment wetting: ?Solid pigments are added to a liquid medium, and air on the surface of the pigment remains attached to the pigment, preventing wetting. Using a wetting agent, which lowers the surface tension at the interface of the pigment and the liquid, displaces the air and ensures the complete wetting of the pigment.
2.????? Deagglomeration: Larger agglomerations of pigment, which form because of intermolecular force, must be broken up to reduce particle size. This is achieved through mechanical shear via a grinding mill.
3.????? Stabilization: ?Pigment dispersants provide either electrostatic or steric functionality that prevents reagglomeration, creating a stable pigment suspension. Simply put, pigment dispersants absorb into the pigment particles, keeping them separated.
Why Are Pigment Wetting Agents & Dispersants Important?
Selecting the right wetting agent and dispersant is crucial for formulating paint, inks, and coatings. Improper pigment dispersion can cause a myriad of visual and performance issues, including color inconsistency, lack of gloss, and foaming. Pigments are very costly, so to reduce cost and achieve optimal appearance and physical properties in ink, paint, and coating formulations, the proper wetting and dispersion of pigments are necessary. In addition, some wetting agents can provide multifunctional benefits, including eliminating issues such as surface defects, high surface tension, and poor leveling.
If you are interested in learning more about pigment wetting agents and dispersants or how they are used to produce high-quality ink, paint, and coating formulations, check out this article.