news

A controlled flocculation dispersant that uses a special structure to allow one end of the dispersant to bond with the surface of the pigment. On the other end, it will form hydrogen bonds with another dispersant. In this way, the pigment particles are flocculated and brought closer together, but without forming true agglomeration or flocculation. This situation is called controlled flocculation or controllable flocculation. This type of dispersant is called a controlled flocculation dispersant. For paint engineers, coloring is a headache for everyone. For example, the issue of coloring is like being friends with a man or a woman, it requires attention to matching social status. If one is rich and beautiful, or short and poor, their marriage will definitely have problems.

The same goes for coatings. When both pigments are well dispersed, there may be no floating color, and when both pigments are poorly dispersed, there may also be no floating color. Many friends have told me that if I don’t add dispersants to my paint, it won’t float, but if I do, the float will be even more severe. This is related to inappropriate selection of dispersants. When the dispersant selection is inappropriate, it actually increases the difference in the dispersion state of the pigment. In coatings, inorganic pigments and titanium dioxide are often particularly easy to disperse. Organic pigments and carbon black are often difficult to disperse, which can easily result in floating white or floating inorganic pigments when combined.

And controlled flocculation dispersants can preferentially adsorb on the surface of inorganic salts or titanium dioxide. By reducing the ability of pigments to move and balancing the differences in the movement ability of different pigments, it is possible to prevent the system from floating and blooming, especially for floating white or inorganic pigments.

In addition, this flocculation system also increases the low shear viscosity of the system, which can provide this thixotropy and increase the resistance to the movement of pigment particles. Some controlled flocculation dispersants may also add a small amount of organic silicon leveling agent to prevent or reduce the Benard vortex and increase the anti foaming effect.

Due to the formation of a three-dimensional spatial structure through controlled flocculation, the coating system exhibits thixotropy. At the same time, it can also have the effect of preventing sagging or dust. Due to the above reasons, controlled flocculation can also lead to a decrease in leveling, as well as stable foam thickening, thixotropy, and other adverse effects.

Meanwhile, the compatibility of these dispersants with most resins is limited, which can also affect gloss and fullness. So, this type of leveling agent is usually used for systems that do not require high appearance requirements, such as anti-corrosion coatings in primers, as well as back coats for transfer coatings, and so on.

Of course, it can also be used for decorative topcoats, but the dosage should generally be controlled within 1 ‰ to 5 ‰, and normally within 3 ‰. For flocculent dispersants, they firmly adsorb onto the surface of pigment particles through anchoring groups.

Then, the stretching base relies on the stretching chain segments to form spatial displacement around the pigment particles. The coagulation between pigment particles can be stabilized in a dispersed state above 20nm. Polymer dispersants can control the movement speed of raw material particles, achieving a state of equilibrium in the movement speed of various raw material particles.

A flocculant dispersant that can reduce the viscosity of the system and improve the flowability of the coating system. The viscosity of this system is close to that of Newtonian fluids and is almost unaffected by shear forces. At the same time, the particles of the pigment obtained from the flocculation type system will be relatively small, which will increase its luster, improve leveling, enhance its coloring power, and increase its coverage or transparency. For materials with electricity or transparent iron oxide carbon black, the better the dispersion, the better the transparency. For titanium dioxide, the better the dispersion, the better its coverage. So, flocculent dispersants are mostly used for high demand topcoats, specifically for dispersing transparent iron oxide, titanium dioxide, and inorganic salt materials.