Sulphur Black Dyestuff for Paper
Sultan Black P product range focusing new production technology, ecological and application performance that are compliant with environmental aspects, trends, health and safety standards of 21st Century’s paper industry. Sulphur dyestuffs are insoluble in water. They must be converted into soluble leuco compounds by means of reduction in an alkaline medium with reducing agent.
Biodegradability, toxicity or pollution of water and air are not taken into consideration with reducing agent. Since in the reduction of sulphur dyes to give leuco sulphur dyes there are formed inorganic polysulphides (mainly Na2S, Na2Sx and/or NaHS) and some sulphide in excess may be present, which constitute a disturbing component in the final product as it cause development of H₂S when handling the dye or when dyeing with it, and/or results in the occurrence of inorganic sulphides in the back-water of the dyeing process.