Why use dispersants-1

Dispersants play a very important role in coating production. The stability of the dispersion system can avoid many coating problems and paint film defects. If the formula is reasonable, adding an appropriate amount of dispersant can effectively reduce costs and improve the performance of the coating. In summary, dispersants have the following functions:

01.Improve gloss and increase leveling effect

Tests have shown that the exact same formula, using different dispersants, will result in significant differences in the gloss of the paint film. For example, in a certain black coil coating system, the 20° gloss of coatings made with three different dispersants are 69.7, 81.5, and 77.1 respectively. If the dispersant used is inappropriate and the color becomes coarse after flocculation, its effect on gloss will be similar to that of matting powder, which will naturally affect gloss.

02.Prevent floating color and blooming

Preventing floating colors and blooming is one of the well-known functions of dispersants. By choosing a suitable dispersant, whether it is blooming in the tank or blooming on the paint film, it can be improved or eliminated. Figure 3 shows the floating and blooming results in the tank after blue paint and white paint made with different dispersants are mixed in the same proportion. There are also some dispersants such as SN-2004, which are controlled flocculation dispersants. The molecular chain contains some carboxyl groups, which are compatible with the pigment and form hydrogen bonds with each other, thereby stabilizing the pigment particles and preventing floating and blooming.

03.Improve tinting strength

The pigments are better dispersed and stabilized, and their tinting power will be significantly enhanced.

04. Reduce viscosity and increase pigment loading

Using a suitable dispersant, the viscosity of the resulting color paste will be significantly reduced. This can increase the amount of pigment loaded and improve production efficiency.

05. Reduce flocculation and increase constructability and usability

Many people do a finger test when evaluating dispersants. If the dispersant is not properly mixed, there will be a significant color difference between the finger-rubbed area and the non-finger-rubbed area. The tinting strength of the flocculated pigment will decrease, which makes color mixing and paint construction difficult. The flow plate test can also be used to observe whether the color paste is flocculated or not.