A process for producing a tetra alkali metal salt of 4,4 '- to - (4 - p - sulfanilino - 6 - diisocyanates of propanol amino - s - triazine - (2) - ylamino) - stilbene - 2,2' - disulfonic

摘要

A process for the preparation of a stable aqueous solution of the tetrasodium salt of 4,4'-bis(4-p-sulfo-anilino-6-diisopropanolamino-s- triazin-2-ylamino)-2,2'-s tilbenedisulfonic acid is disclosed. The resultant solution is substantially free from destabilizing organic impurities and destabilizing inorganic salts. In the absence of these destabilizing materials the solution does not require the co-solvents of the prior art.