Molecular defoamer is a polymer formed by grafting the defoaming active substance directly onto the carrier substance. The polymer molecular chain with wetting effect of hydroxyl, defoaming active substances distributed around the molecule, the active substances are not easy to gather, and good compatibility with the coating system.
Such molecular level defoamers are mineral oil type — FoamStar A10 series, silicone-containing type —-FoamStar A30 series, and non-silicone non-oil polymer type — FoamStar MF series.
Therefore, when people disperse organic pigments and make advanced coatings, they often choose polymer dispersants. They can use most of the anchor groups to be tightly adsorbed on the surface of the pigment, and the extended chain constitutes an effective steric hindrance in the dispersion medium, lubrizol ptfe wax so that the pigment dispersion is in a stable state.
The use of polymer dispersants to prepare color paste has many advantages: reduce the viscosity of the color paste and increase the solid content of the pigment; shorten the grinding time and improve the production efficiency; the pigment particle size is small and the color development is strong: good stability; can provide good Gloss, brightness, hiding power, etc., give the coating excellent performance.
The following three issues must be paid attention to when using polymer dispersants.
The dispersant must be compatible with the resin base
The stable chain of the dispersant must be dissolved in the resin solution to stretch freely to form an adsorption layer with a certain thickness. If it is incompatible with the resin solution, although the dispersant can be adsorbed on the surface of the pigment in this poor solvent, its stable chain is curled up and cannot be stretched freely, and the adsorption layer formed will be very thin, so that it cannot be fully utilized. The role of polymer dispersant. Tests have confirmed that poor compatibility will affect the dispersion efficiency of pigments and coating performance.
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