Role of zinc oxide in industrial paint pigments

Zinc oxide has a high refractive index and has the ability to absorb ultraviolet light, and its coloring and covering power is strong, but its color is pure white and does not chalk, and it has good light and heat resistance. It can form ligand compounds with carboxylate ions in the paint and thus can reduce the sensitivity of water in the coating film. Therefore, zinc oxide can improve the weathering and chalking resistance of the coating film and is suitable for exterior wall coatings.

Zinc oxide has anti-mildew properties and inhibits the growth of microbial fungi. Generally speaking, ceramics, cans and barrels of paint are used with small particle size and high purity of indirect method zinc oxide; indoor paint, latex paint is mostly used with needle-shaped direct method zinc oxide, which makes the oil absorption value higher and can improve the suspension performance.

Zinc oxide has to make the product coating film flexible, firm, impermeable to water, thus can stop the gold Hublot rust. However, it is not suitable to mix with base material with more free acid to produce more zinc soap, which makes the paint sticky and not easy to paint. Zinc oxide is used in anti-corrosion or marine coatings, wax emulsion for concrete curing which can form dense zinc-titanium compounds, reducing the speed of further penetration of corrosive media, mainly to play the role of rust prevention.

Zinc oxide is an alkaline compound and can interact with traces of free fatty acids to form zinc soap, which has a tendency to thicken the paint and dissolve when it meets inorganic acid or acetic acid.

Coating grade zinc oxide has a small particle size and a large surface area, which provides strong adhesion and coverage, thus improving the efficacy of the coating pigment. Zinc oxide for coatings will eventually form a precipitate in use, which has a certain shielding effect against ultraviolet light.