The paint fillers of latex paint are dispersed

of latex paint are usually dispersed in a water-like medium, and then coated with emulsion to make paint. The polarity of the water-based medium is high, and can interact with most pigment fillers and wet its surface, so that dispersion can be carried out, but not controlled, so the pigment dispersant should be used to disperse it better.pigment dispersant is an anion polylyte with a certain surface activity, so it can move spontaneously to the surface. It has a suitable relative molecular mass to form a thick interface layer and stable dispersion, without moving too slowly to meet the requirements of the process.pigment dispersant is adsorbed to the positively charged surface with negative ions and mesos. The charge on the surface of the pigment, especially the metal oxides, has an isoelectrent point (without charge) in the water, so the pH and isoelect points of the dispersed medium should be kept as far away as possible to increase the adsorption density.
the negatively charged surface is first shielded by the compensation of alkali metal cations (fast movement) in the dispersion medium, and then adsorbed with the help of a pro-oil base. Thus, increasing the concentration of alkali metal cations in the dispersed medium can increase the adsorption density. This is the common formula for adding potassium polyphosphate. On the neutral surface, the oil-dependent base is attached to it, and these adsorbed pigment dispersants extend to the body in dissogradation of the base group, and the pigment particles are dispersed in the medium by charge refringing and spatial shielding.organic pigments are highly hydrophobic, pigment dispersants are not active enough, so often with surfactants, first with oil-dependent sorbentation to reduce the degree of hydrophobic, so that pigment dispersants can be adsorbed. Since pigment dispersants have multiple adsorption groups, they do not fall off easily under dynamic adsorption, thus gradually replacing surfactants.Titanium dioxide is the most commonly used pigment in latex paint, its isoelectrides vary from surface treatment to surface, and those far from the dispersion medium pH have a higher surface charge density, resulting in a higher pigment dispersant adsorption density. Figure 1 is the adsorption of olefins/shunbutene dates used in titanium dioxide dispersion treated with alumina surface treatment (about 6.4 isoelectric point) and silica surface treatment (about 1.2 isoelectric point), from which it can be seen that the adsorption at the same pigment dispersant concentration is far from.