Thiourea dioxide

Thiourea Dioxide

CAS Number: 1758-73-2

Description Thiourea dioxide is also called formamidine-sulfinic acid or aminoiminomethanesulfinic acid and is often abbreviated as TDO or TUD. Thiourea dioxide is a powdered stable compound, which dissolves in water and decomposes gradually to produce sulfoxylic acid through formamidine-sulfinic acid to exhibit a reducing action. This reaction is promoted by the application of heat or in the presence of an alkali, and a strong reducing action is thereby exhibited. But, this reaction is slow, and particularly in an acidic to weakly alkaline region

Technical Information Chemical Name: Thiourea Dioxide Synonyms: Formamidine sulfinic acid, FAS, TDO Molecular Formula: CH4N2O2S Molecular Weight: 108.11 CAS Number: 1758-73-2

 Product Properties Standard Specifications Purity, %: Min. 99.0 Thiourea, % :Max. 0.1 Moisture,% :Max. 0.05 Iron (Fe), ppm: Max. 10 Sulphate, % :Max. 0.17 Appearance :White crystalline powder Packing:25 kgs kraft paper bag or 50kgs in fiber drum  

Applications Thiourea dioxide (TDO) is a strong reductant which re-arranges under alkaline conditions to form formamidine sulphinic acid. This product is used in leather processing industry, paper, pulp and board industry, photographic industry, textile processing industry, bleaching and reducing agents. This product is also a component of decolorisation agents. TDO bleaching has recently come to be spotlighted as a substitute for NaClO bleaching in bleaching of waste wood-free or mechanical paper and as a substitute for Sodium Hydrosulfite bleaching in post-bleaching after hydrogen peroxide deinking/bleaching of waste newspaper, from the viewpoint of the problem of waste water pollution by organic chlorine compounds represented by dioxins, demand for energy conservation, decoloring effect on dye type coloring materials, etc. TDO bleaching has a considerable decoloring effect on dye type coloring materials, like Sodium Hydrosulfite bleaching, and TDO has a property of reacting with oxygen in air slowly as compared with Sodium Hydrosulfite. Even when a presently used NaClO bleaching equipment is diverted as it is, a loss due to oxidative decomposition is relatively small and a bleach brightness equal to that attained by NaClO bleaching can be attained by choosing a suitable using amount of TDO. TDO undergoes relatively rarely oxidative decomposition by oxygen in air. TDO bleaching is suitable for bleaching pulp having a high consistency by usual equipment while achieving a saving in energy. TDO has been very effective on a wide variety of pulp sources as a reductive bleaching aid in the pulp and paper industry. The application of TDO is crucial to achieve optimal brightness gain in the deinking process.