With the development and application of water-based latex paint, the choice of latex paint thickener is diversified. Adjustment of rheology and viscosity control of latex paints from high, medium and low shear rates. Selection and application of thickeners for latex paints and latex paints in different emulsion systems (pure acrylic, styrene-acrylic, etc.).
The main role of thickeners in latex paints, in which rheology is one of the important factors that constitute the appearance and performance of paint films. Also consider the effect of viscosity on the pigment precipitation, brushability, leveling, fullness of the paint film, and the sag of the surface film during vertical brushing. These are quality issues that manufacturers often take into account.
The composition of the coating affects the rheology of the latex paint, and the viscosity can be adjusted by changing the concentration of the emulsion and the concentration of other solid substances dispersed in the latex paint. However, the adjustment range is limited and the cost is high. The viscosity of latex paint is mainly adjusted by thickeners. Commonly used thickeners are: cellulose ether thickeners, alkali-swellable polyacrylic acid emulsion thickeners, non-ionic associative polyurethane thickeners, etc. Hydroxyethyl cellulose ether thickener mainly increases the medium and low shear viscosity of latex paint, and has a large thixotropy. Yield value is large. The hydrophobic main chain of the cellulose thickener is associated with the surrounding water molecules through hydrogen bonding, which increases the fluid volume of the polymer itself. The space for free movement of particles is reduced. The viscosity of the system is increased, and a cross-linked network structure is formed between the pigment and the emulsion particles. To separate the pigments from each other, the emulsion particles rarely adsorb.
Post time: Nov-02-2022