Coating dispersant classification – Fatty acids, aliphatic amides and esters

Stearamide and advanced alcohols can be used to improve lubricity and thermal stability, the amount (mass fraction, the same below) 0.3%-0.8%, can also be used as a slip agent for polyolefins.

Hexenyl bis-stearamide, also called ethylenyl bis-stearamide, is a high melting point lubricant, the dosage is 0.5%-2%.

Stearic acid monoglycerides, triglycerides; oleoyl dosage of 0.2% to 0.5%; hydrocarbon paraffin solids, melting point of 57 ~ 70 ℃, insoluble in water, soluble in organic solvents, resin dispersion, compatibility, thermal stability are poor, the dosage is generally less than 0.5%.

Electrically neutral wetting and dispersing agent
Electrically neutral wetting and dispersing agent means that both anions and cations in the compound contain organic groups of the same size, and the entire molecule is neutral but polar. For example [CH一(CH) -CH 2-NH] -OOC-CH 2-(CH 2), -CHs].

This kind of wetting and dispersing agent is used in paints in a large amount and has a wide range of applications. Almost every paint additive manufacturer has such products.

2. Application mechanism of low molecular weight wetting and dispersing agent
This type of wetting and dispersing agent is a surface active agent, which can be firmly acid modified pe wax adsorbed on the surface of the pigment particle through the interaction between the polar groups with the inorganic pigment, and can also be ionized and charged to generate electrostatic adsorption. Non-ionic wetting and dispersing agents do not have active groups and will not produce chemical adsorption. Most of them are used as wetting agents for water-based coatings. When used in conjunction with other ionic dispersing agents, they can provide good dispersion stability.
The polar groups of this type of dispersant are adsorbed on the surface of the pigment particles, and the other end spreads toward the dispersion medium, causing steric hindrance, but the effect is not very satisfactory due to the low molecular weight.

The wetting and dispersing agent is adsorbed on the surface of the pigment particles, replacing the moisture on the surface of the pigment, reducing the interfacial tension between the pigment and the resin solution, improving the wettability of the resin dispersing agent to the pigment, and improving the affinity between the resin solution and the pigment sex. They are usually not oriented at the liquid/gas interface and the coating/substrate interface. Their molecular structure determines their adsorption selectivity, which is mainly oriented at the interface between the resin liquid and the pigment. Therefore, the surface tension of the coating and the adhesion to the substrate are generally not affected.