Durabo White, 24.5 per cent zinc sulphide, 51 per cent barium sulphate, 18 per cent white clay, 5.5 per cent infusorial earth.
Titanium dioxide, a versatile and widely used material, finds its application in various industries including the rubber industry. This white pigment is known for its excellent UV resistance, durability, and opacity, making it an ideal choice for enhancing the properties of rubber products.
Having thus described the origin and uses of the pigment, we now come to the question, what is lithopone? It is, in short, a chemical compound usually consisting of 30.5 per cent zinc sulphide, 1.5 per cent zinc oxide and 68 per cent barium sulphate, but these proportions vary slightly in the different makes. Lithopone of this composition is sold as the highest grade, either as red seal or green seal, as it best suits the idea of the manufacturer. Many manufacturers, especially in Europe, sell and also export other brands under other seals, containing 24, 20, 18 and as little as 12 per cent of zinc sulphide with very small percentages of zinc oxide, the balance being usually barium sulphate, but sometimes certain portions of China clay or gypsum (calcium sulphate) or whiting (calcium carbonate). Such brands are not a chemical compound, but mechanical mixtures of the chemically compounded lithopone and the admixtures referred to.