The chemical formula of iron oxide yellow is Fe2O3·H2O. Due to the presence of crystal water, its heat-resistant temperature is: lower than 140/℃, no discoloration, dehydration at 270-300/℃, and reddening, and the color gradually turns red and finally becomes iron red. It is widely used in plastics and plastic products. By coating the surface of the iron yellow, the iron yellow pigment can be used in certain high temperature applications. Zinc Iron Yellow (C.I. Pigment Yellow 119) has a chemical composition of zinc ferrite with a brownish-yellow hue.
Main properties of iron oxide yellow pigment: It is bright yellow, almost equal to chrome yellow, has strong covering power, very stable effect on light, and light fastness can reach grade 8. Has good weather resistance. Iron oxide yellow is only suitable for coloring of rubber, EVA, etc. due to its poor heat resistance. The price is relatively low and it is non-toxic and is mostly used in light colors and toning. Combined with phthalocyanine blue and phthalocyanine green to produce composite iron phthalocyanine green for making artificial turf and other similar products.
In order to improve its heat resistance, the yellow iron oxide is coated with a mixture of silicon oxide and aluminum oxide, and sodium silicate solution is added to the fully dispersed iron yellow suspension, and then the pH value is adjusted to neutral with acid, and silicic acid Sodium forms silicic acid and is hydrolyzed into silica and precipitates on the surface of iron yellow particles. The coated iron oxide yellow pigment has heat resistance up to 260℃, and has good light resistance and weather resistance.
