Zinc Oxide

About This Product

Zinc oxide, ZnO with CAS number 1314-13-2, is a fine white powder, insoluble in water and amphoteric, dissolving in both acid and strong alkali. It is produced by the indirect French process, which gives a high-purity product, or the direct American process from ore. Rubber accounts for most of its consumption, and its role there is specific. Sulphur vulcanisation of rubber proceeds far too slowly to be commercial without accelerators, and the accelerators themselves are largely ineffective without an activator. Zinc oxide, usually with stearic acid to form soluble zinc stearate in situ, provides zinc ions that complex with the accelerator and dramatically increase the rate at which sulphur crosslinks form, while also improving the heat resistance and the density of the resulting network. Its second major use rests on a quite different property: zinc oxide absorbs across the UVB and UVA bands and scatters visible light, which makes it a broad-spectrum physical sunscreen filter that works by sitting on the skin rather than being absorbed, and it is one of very few filters approved worldwide. It is also a semiconductor, a ceramic glaze component and a feed micronutrient. It is used in rubber vulcanisation, sunscreens and personal care, ceramics and glazes, paints and pigments, animal feed and in varistors and electronics. Bio Green Chem supplies zinc oxide grades to specification on ZnO assay, surface area, particle size, lead, cadmium, acid-insolubles and loss on ignition.