An indispensable dispersant?
The dispersant is to reasonably disperse various powders in the solvent, through a certain charge repulsion principle or polymer steric hindrance effect, so that various solids are stably suspended in the solvent (or dispersion). Dispersant is a surfactant with two opposite properties, lipophilicity and hydrophilicity in the molecule. It can uniformly disperse solid and liquid particles of inorganic and organic pigments that are difficult to dissolve in liquids.
The highly efficient and environmentally friendly water-based dispersant is non-flammable and non-corrosive, can be infinitely compatible with water, and is insoluble in organic solvents such as ethanol, acetone, and benzene. It has excellent dispersing effect on kaolin, titanium dioxide, calcium carbonate, barium sulfate, talc, zinc oxide, iron oxide yellow and other pigments. It is also suitable for the dispersion of mixed pigments. The functional characteristics of water-based dispersants are explained as follows:
1. Instead of ammonia and other alkaline substances as neutralizers, reduce the smell of ammonia and improve the production and construction environment.
2. Water-based paint dispersant can effectively control the PH value and improve the efficiency and viscosity stability of the thickener.
3. Improve the dispersion effect of pigments, improve the sinking and re-coarse phenomenon of pigment particles, improve the color development of the color paste and the gloss of the paint film
4. Water-based paint dispersant is volatile and will not stay in the paint film for a long time. It can be used in high-gloss paints and has excellent water resistance and scrub resistance.
5. It can be used as a post additive to effectively reduce the shear viscosity and improve the fluidity and leveling of the coating.
Water-based dispersant is also an indispensable additive in the coating industry. Contribute to the dispersion of paint pigments and fillers. Make the coating easier to disperse and even. In addition, it also plays a role in smoothing the coating during the film forming process.
The other end of the effective concentration range of the dispersant is the "aggregation concentration value", which is the concentration of the dispersant necessary to prevent the pigment from aggregation and flocculation under very harsh conditions. In latex paint systems, the optimal dispersant concentration required for pigments is between the above two values. Experimental method for determining the amount of dispersant: The determination of the required amount of dispersant to effectively disperse solid pigments in the latex paint system is carried out through a titration operation step with two endpoints. The two titration endpoints are the pour point and the concentration value .
Effective concentration of dispersant: In the latex paint system, each type of pigment and filler needs a certain amount of dispersant to disperse. For a given dispersant, there will be an effective concentration range that stabilizes the system. The lowest point of this range is called the "flow point", and its meaning is the concentration of dispersant required for the flow state of the pigment or filler wetted with water, that is, the minimum amount of dispersant necessary to suspend the pigment.